Should I go to ER or wait?

This is my second pregnancy and with my first (5 years ago) I was very sedentary and use to being super careful. Within finding out I was pregnant, I helped my mom move out of her house, and moved me and my son out of ours within a couple months. I'm now 13 weeks and just got my apartment unboxed and settled. I know you're not supposed to lift heavy things but I've had to lift extremely heavy things because of circumstance of moving and didn't really have much help. I don't have another appointment with my OB til the end of May and I'm worried everyday if my baby is ok. I was thinking of just going to the ER so they can check and make sure. I've had boxes shoved into my stomach and have fallen a few times carrying things. I'm so panicked, should I wait or just go? I was worried about the hospital bil but at this point I just don't care anymore. What do you think I should do? Any advice?