Why am I in pain?

I’m 19 weeks and have been having pain on my lower ab and back since Monday night! Sometimes it hurts so bad I can’t stand up straight. I’ve tried Tylenol but that doesn’t help at all. This whole thing started after a fight between husband and I and now it just won’t go away! I have two kids and I’m a stay home mom with no help at all. my youngest is 2 which doesn’t help much in the part of just relaxing and laying down. What could this pain be from and why???!!!!! 😭😭😭