help.!

okay this maybe a dumb question but i am a ftm.! okay so i'm having a crap like pains but they're more intense and a bit different they start in the middle of where my normal craps are but then the pain spreads towards my hips. also when i get them i feel the need to go poo. are these pains contractions or braxton hicks.? i'm so confused or am i just having more intense cramping.? i'm 38+1 weeks i don't know if that makes a difference.