You’re right — this is hormones, doing their thing. And, they're the culprits behind morning sickness, mood swings, fatigue, vision changes, sinus congestion and postnasal drip. Oh yeah, hormones also affect your hair and nails, and contribute to heartburn, constipation and that incessant need to pee. Try to look on the bright side: These very same hormones are making your uterus the perfect home for growing baby, and will help your muscles relax during delivery. And remember — these strange symptoms will eventually subside, and your little darling will make all you endured well worth it.