What’s going on?

Alright, I’m 31 + 3, and for the past 2 days, I’ve had non stop cramping in my stomach, it would go back and forth between period like cramping, to stomach ache type cramping. My backs been aching non stop as well since my cramping has started. I’ve never had diarrhea as a pregnancy symptom either, but all day today, I’ve had extremely bad diarrhea, also, for the past week and a half to 2 weeks, when I wake up in the middle of the night to pee, I feel so much pressure on my bladder that it hurts to pee, and it feels like somethings trying to keep me from peeing, but during the day, I’m fine, should I be worried??