What Happens to Your Body During Pregnancy?

The starting point is obviously conception, when the embryo implants. As the hormone HCG increases, dreaded "morning sickness" kicks in. Breast tenderness, sensitivity to smells, larger, darker nipples, and a "pregnancy glow" are all hallmarks of the first trimester (the first three months of pregnancy).

The second trimester is a bit more fun, with decreased HCG giving you energy back. Caution: You can definitely feel sexier, more energetic, and blood flow may even improve orgasms. Your hair and nails can even get thicker due to an increase in estrogen. Score. Though, this is also the time in your pregnancy where you'll feel a bit clumsy and start getting weird cravings. You may also experience carpal tunnel syndrome, acid reflux, and sciatica—guess it can't all be sunshine and daisies.

By the time your eighth month rolls around, expect to get up in the middle of the night to pee a lot as your uterus pushes on your bladder. There will also be pressure on your lower abdomen as you prepare for delivery. Labor is, perhaps, the hardest part of it all. Some experience hot flashes, chills, and nausea when delivering vaginally. Birth stories vary widely, so choose your own adventure from here on out. Because the next step? Well, that's welcoming your little bundle(s) of joy. And that's where the real work begins.

In a follow-up to its viral video, "Your Period in 2 Minutes," Glamour is back with a new video that perfectly breaks down the science, symptoms and signs of pregnancy, from the moment you first see that positive pregnancy test to the day you meet your little one for the first time.