at what point should you go to the ER for cramps?

I have had really bad cramps for like three weeks and it's like on and off. Lately they've been getting worse it feels like  today they hurt really bad and it's night time so no place is open and idk I took pain killers but I'm just wondering at what point should you go to the ER for cramping? Do you have to be on the floor sobbing? I'm not at that point but they hurt really bad and really deep
I'm not pregnant I don't think and it's been three weeks but they're on and off sometimes I can go a day or two without them but then they'll come back it's like period cramps but no period. I'm just afraid of going there and then telling me I'm fine and I'm overreacting and then I get billed a huge bill