When Does Implantation Occur? Experts Explain the Timeline
When I was pregnant with my fourth baby (but didn’t know it yet!), I was standing in my kitchen and felt a few twinges in my pelvis. I assumed it meant my period was coming soon, since we’d had a few unsuccessful attempts to conceive. Over a week later, I was shocked to learn I was pregnant—and those twinges were likely implantation cramps.
Implantation is one of the first behind-the-scenes processes your body goes through that set the stage for baby’s arrival, long before you have obvious signs of pregnancy. So exactly when does implantation occur, what does it entail and are there implantation symptoms to look for? Here’s what you need to know.
- What is implantation? Implantation is a process in early pregnancy when the blastocyst, aka developing fetus, embeds itself into the wall of the uterus.
- When does implantation occur? Implantation happens after fertilization, and usually sometime between 8 and 10 days after ovulation.
- Implantation symptoms can include mild cramping, bleeding and nausea. Many people experience no symptoms at all.
- How soon after implantation can I test? It’s best to wait until after your missed period to take a pregnancy test.
Implantation is an important process that takes place in early pregnancy. It’s when “the blastocyst—what the cells are called at this stage of pregnancy development—invades into the wall of the uterus,” explains Julie Lamppa, APRN, CNM, a nurse-midwife at the Mayo Clinic in Rochester, Minnesota. Basically, the developing fetus is embedding itself into the uterus.
To simplify: Implantation occurs after ovulation and fertilization and before you get a positive pregnancy test.
There are a few important steps that kickstart your pregnancy and implantation is one of them. First, fertilization occurs; this is when an egg and a sperm meet in the fallopian tube to form a single cell, according to the American College of Obstetricians and Gynecologists (ACOG). From there, the cell divides into multiple cells and moves through the fallopian tube to the lining of the uterus. There, it implants and starts to grow.
The timeline for this can vary, but there are ways to estimate when implantation occurs by measuring against ovulation and perceived conception—more on this soon.
I started having a kind of twinge-y tightness that I often get with my period about eight days past ovulation. Actual cramps started about 11 days past ovulation. I was convinced I was getting my period because they felt just like the cramps I get with it. I tested that same day and—BAM!—a big fat positive!
How long after ovulation does implantation occur?
Every woman’s cycle is a bit different, so it’s difficult to put an exact number of days on this process, and ranges will vary, says Dr. Michael Cackovic, MD, an ob-gyn and maternal-fetal medicine specialist at Bridgeport Hospital in Connecticut. However, implantation usually happens sometime between 8 and 10 days after ovulation (aka the release of a mature egg).
Of course, not everyone knows exactly when they’re ovulating. In a typical 28-day cycle, a woman would likely ovulate around day 14, per the Mayo Clinic.
Many women don’t have regular cycles, though. To that end, you’ll want to be on alert for certain symptoms of ovulation, including changes in cervical mucus and increased discharge. You can also try taking an ovulation test for more definitive intel.
How long after conception does implantation occur?
Again, this can depend a bit. Lamppa says that the blastocyst usually implants in your uterine wall about 6 to 10 days after it’s been fertilized by sperm. There’s about a 12 to 24-hour window for fertilization to happen during ovulation.
However, sperm can live in your body for up to five days before ovulation, so from sex to fertilization to implantation, it can take anywhere from 6 to 15 days total—give or take—depending on the timeline and your unique cycle.
How long does implantation take?
Once again, the exact time frame varies, says Lamppa. There’s a lot happening that you won’t see or feel. But, generally speaking, implantation will take place over the course of several days, starting about six days after fertilization and continuing as the blastocyst burrows itself deeper and deeper into the uterine wall.
Most people don’t feel implantation. It's a microscopic process where the embryo attaches to and begins to enter the uterine lining, so there’s usually no distinct sensation.
In general, implantation symptoms can mimic what you’d experience with your period, Dr. Cackovic says. They can include:
- Light bleeding or spotting
- Cramping
- Nausea
- Bloating
Implantation bleeding or discharge—if it happens at all—is more likely to occur first, midwife Lamppa says. “It’ll typically be brownish-red in color and should not contain clots,” she says. “It may occur right around the time you think you may be getting your period, but then you don’t continue to bleed like a normal period.”
The other symptoms usually don’t start until a few days after implantation has happened, when the levels of the pregnancy hormone human chorionic gonadotropin (hCG) start to rise in your body, Lamppa adds.
I had a scant, brownish discharge for one day about three days before my period was due—I thought that I was getting my period early and that I had had yet another unsuccessful month of TTC. The spotting stopped and my period never came. I did my pregnancy test about three days after my period was due, and it was positive!
In general, “discomfort from implantation should be very minimal, with no intervention needed,” Lamppa says. But if you’re feeling uncomfortable, you can use a warm compress on your pelvis, suggests Dr. Christine Greves, MD, an ob-gyn at the Winnie Palmer Hospital for Women and Babies in Orlando.
If you’re having more intense pain that doesn’t seem normal, call your doctor for guidance. It could be something else.
After implantation, the blastocyst grows and hCG levels will start to rise. Nurse-midwife Lamppa says that “the complex cellular changes of early pregnancy continue.” Nine weeks after fertilization, the embryo officially becomes a fetus, according to ACOG.
It’s tempting to want to take a pregnancy test right away when you suspect you might be pregnant. But Dr. Greves explains that suspected implantation shouldn’t be your cue to take a test.
While some pregnancy tests claim they can detect positive results six days before your missed period, waiting until after your anticipated period is your best bet. “This will give you the accuracy you’re looking for without questioning faint lines or wasting tests that show negative results,” Lamppa says.
There’s a lot that happens on your journey to implantation. Here’s what you can expect.
- Ovulation. This is when your ovary releases an egg.
- Fertilization. After sex, your partner’s sperm will travel to your fallopian tube where it may fertilize your egg.
- Division. The fertilized egg divides as it travels toward your uterus.
- Blastocyst. About five or six days after fertilization, the embryo becomes a blastocyst (a fluid-filled ball of rapidly dividing cells) and can start implanting in your uterine lining.
- Implantation. Once this happens, early cells that will become the placenta start making hCG. This is the hormone that’s detected by pregnancy tests. However, it will take several more tests for hCG to rise enough to be detected on a home urine test.
While implantation should hopefully be seamless, there are some possible complications that can occur. These include:
- Late implantation. When implantation happens more than 12 days or so after ovulation, it’s considered late. Lamppa says this has been linked to early pregnancy loss.
- Ectopic pregnancy. An ectopic pregnancy happens when a fertilized egg implants and grows outside the main cavity of the uterus. Lamppa explains that ectopic pregnancies most commonly occur in the fallopian tubes but can also occur in the ovary, prior cesarean scars or the cervix. This type of pregnancy is never sustainable and can even be life-threatening without timely attention and care.
Frequently Asked Questions
What is an implantation dip?
An “implantation dip” is a term used to describe a one-day drop in basal body temperature that you’d usually notice around 7 to 10 days after ovulation, Dr. Shahine says. The idea is that “a transient rise in estrogen at the time of implantation can lower basal body temperature,” she explains, adding that while it’s a popular concept in some online charting communities, science doesn’t strongly support the implantation dip as a reliable pregnancy predictor.
How many days pregnant are you at implantation?
“Biologically, implantation usually happens about 6 to 10 days after ovulation and fertilization,” says Dr. Dana McQueen, MD, an ob-gyn and reproductive endocrinologist at RMA Northern California – San Francisco. “Clinically, pregnancy is dated from the first day of the last menstrual period, not from fertilization. So, implantation usually corresponds to being 3 weeks pregnant, or roughly 20 to 24 days after the last period in someone with a typical 28-day cycle.”
What are the five stages of implantation?
The five stages of implantation are generally considered: hatching, apposition, adhesion, invasion and early placental development, says Dr. McQueen. “In plain language, the embryo has to hatch out of its outer shell, come into contact with the uterine lining, attach, begin to enter the lining and then start the early process of placental development,” she explains.
How long does implantation last?
“The active phase of implantation—from the moment the blastocyst first touches the endometrium to the completion of trophoblast invasion—takes approximately four to five days,” Dr. Shahine says. “It typically begins 6 to 10 days after ovulation and is largely complete by about day 12 post-ovulation.”
When it comes to the complex changes that happen during pregnancy, fertilization and implantation are just the beginning. If you’ve been trying to conceive and are hyper-aware of what’s happening in your body, you might notice some implantation symptoms. And if you feel nothing? No worries; it’s still very much a possibility.
The only way to definitively know if implantation has occurred—aka you’re pregnant!—is to test in a few days once you miss your period. There’s a lot happening inside that wondrous body of yours—try to not stress.
Many hopeful moms-to-be wonder whether that little cramp was implantation—or if their period’s about to start. To demystify the process and help readers understand exactly when implantation occurs, we consulted four ob-gyns and a nurse-midwife. We also consulted sources such as The American College of Obstetricians and Gynecologists (ACOG) and Mayo Clinic. Finally, we scoured The Bump’s community forums to find real-mom experiences. After editing, this article was vetted through fact-check and reviewed by our ob-gyn medical adviser. Learn more about how we ensure the accuracy of our content through our editorial and medical review process.
About the author: Korin Miller is a mom of four—who, during her fourth pregnancy, mistook implantation cramps for pre-menstrual pain. (Only to be pleasantly surprised!) As an experienced health and pregnancy writer and parent, Korin infuses every article she touches with empathy and words of personal wisdom. Her work has appeared in publications such as Women’s Health, Prevention, Cosmopolitan and The Washington Post.
Please note: The Bump and the materials and information it contains are not intended to, and do not constitute, medical or other health advice or diagnosis and should not be used as such. You should always consult with a qualified physician or health professional about your specific circumstances.
Plus, more from The Bump:
Dr. Michael Cackovic, MD, is an ob-gyn and maternal-fetal medicine specialist at Bridgeport Hospital in Connecticut. He received his medical degree at the MCP Hahnemann University College of Medicine.
Dr. Christine Greves, MD, FACOG, is an ob-gyn at the Winnie Palmer Hospital for Women & Babies in Orlando. She received her medical degree from the University of South Florida College of Medicine.
Julie Lamppa, APRN, CNM, is a nurse-midwife at the Mayo Clinic in Rochester, Minnesota, and co-author of Obstetricks(https://www.amazon.com/exec/obidos/ASIN/189300564X?&linkCode=ll1&tag=tb-when-does-implantation-occur-20&linkId=54d89726590deb77f5c18209a4026173&language=en_US&ref=asli_ss_tl).
Dr. Dana McQueen, MD, MAS, is an ob-gyn and reproductive endocrinologist at RMA Northern California – San Francisco. She received her medical degree from the University of California Irvine School of Medicine.
Dr. Lora Shahine, MD, FACOG, is an ob-gyn and reproductive endocrinologist at Pacific Northwest Fertility. She received her medical degree from Wake Forest University School of Medicine.
The American College of Obstetricians and Gynecologists, How Your Fetus Grows During Pregnancy, December 2021
Mayo Clinic, What Ovulation Signs Can I Look Out For if I'm Trying to Conceive?, December 2022
American Pregnancy Association, Fertility Window Calculator
The New England Journal of Medicine, Time of Implantation of the Conceptus and Loss of Pregnancy, June 1999
Cleveland Clinic, Conception, September 2022
The American College of Obstetricians and Gynecologists, Trying to Get Pregnant? Here’s When to Have Sex, August 2025
Medline Plus, Cell Division, August 2025
Real-parent perspectives:
- sapgirl76, The Bump community member
- wendyshrief, The Bump community member
Learn how we ensure the accuracy of our content through our editorial and medical review process.
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