Sometimes your baby finds a comfy spot on one side of your stomach or the other side sometimes bruising your insides I know exactly how you feel. This should be normal. Drink lots of water or take a warm bath to see if it goes away
It's sounds like BH from my research but I am only 16 weeks with my first sticky baby so I haven't had personal experience. Maybe if it doesn't get better by morning or if it gets worse call the doctor to see what they think.
I've been Layon n bed for over an hr the pain comes n goes but the tightness is constant
I looked this up and there is like nothing on breathing and sides hurting :/ but a lot of women said stuff about gas and BH idk if this helps at all. Try to relax and get comfortable as possible your almost done.