It definitely sounds like a muscle, you can ice it to try to relieve some pain. I feel you on the Tylenol thing. Useless crap lol you're almost done though, good luck!
I took tylenol but it doesnt even help. It just ***** that i can go into labor any second and this pain is unbearable
It could be pulled muscles or even a bruised or cracked rib... not much you can do but take tylenol for the pain and let it heal on its own