Thanks y'all! I was slacking on my drinking! That's probably what it is!
You get them when your dehydrated. You need more water
They start very early, but aren't usually felt until later. You can feel them probably start around 15 weeks sometimes. They are random tightenings or cramps typically only affecting part of the uterus rather than the entire thing. They come and go randomly. They don't really hurt but they can be very noticeable. Drinking lots of water and resting can help reduce them sometimes.