Labor?

So I feel like I have to poop, I tired and only pooped a little. My belly is hurting like I have to go but nothing more is coming out but even when I pass gas it doesn’t relief the stomach ache and it kinda comes and goes, the pain feels like diarrhea/period cramps. I can’t tell if my stomach is getting hard or not..I’m 29 weeks pregnant tomorrow.. could this be labor?