38 weeks with cramps

Have gotten really uncomfortable starting yesterday. Lots of tightness & cramping (feels like running side cramps except they're stretching across my mid-belly), which I never experienced with the other two. I think I was dehydrated, because since then I pounded 3+ large Nalgenes of water and the cramps have been better. I also think I strained my ab muscles doing snatches yesterday. Everytime the baby kicks it feels like he's pushing on a bruise. Ugh! Just gonna walk as much as I can with the cramping and abdominal pain.
38 weeks
am:
2 mile walk that felt tough b/c of cramping
pm:
2 mile walk with only some cramps and mild contractions