I Keep Feeling Like My Rib Is Popping Out Of

i keep feeling like my rib is popping out of place in the back. after i feel it pop back my muscles are really sore back there. I also get a lot of sharp pain in the front and it only lasts a minute or less. When this first started my trainer told me i popped a rib out or it was caused by my shoulder. One day I was laughing (which it hurt to laugh) and all of a sudden you just heard a bunch or cracks and pops and it felt better after but still get the pain. When I raise my arm is when I notice my rib on my upper left back the most. Th front is like a sharp pain that makes me tense up some. No clue what is going on, any advice?