Labor... or just pain

I've tried Google, but it's all like "labor feels different for everyone" without actually listing all the different ways it can feel.

So at the moment, I've had a pretty normal day just regular housework, nothing too strenuous, and now I'm having pretty harsh pain. It pretty much feels like I have my period, like crampy aching that doesnt go away in my lower back and pelvis.

I've also had wet underwear from what I assumed was discharge but I havent really had discharge this whole pregnancy so it's something new.

Just wondering if this kind of neverending period pain is normal for no reason or if it could be a labor sign? I'm 36+2 and have had a completely textbook pregnancy until now