Should I be worried, or is this normal

So last night me and DH had sex, well we went to sleep sometime after, all night I had backaches, today I’ve had back aches all day and cramping in my lower stomach and some tightening here and there. TMI, I thought it might be me needing to poop, eventually I pooped but I’m still having all those things happening. Not consistent. I am 36 weeks 1 day today.