What’s the difference?

Ni

So I’m 35+4 and I’ve been cramping off and on since Friday, I had a NST on Friday and I was having Braxton Hicks(mild contractions), but I’ve had the sudden urge to poop and period cramps. Definitely not constant, but when I have the period cramps they don’t make my uterus hard like the Braxton Hicks do. I’m just wondering if the period cramps are early labor? Does my uterus have to be hard in order for it to be an actual contraction? Please women that have only had their babies or had children prior.