My shoulder pops out 1-2 times a month...Doctors say im fine but i know im not!...what should i do?

My shoulder pops out or it definitely feels that way.. when i play basketball..im guessing it happens due to certain movements i do with my arm...both shoulders do this. It happens one to two times a month. Sometimes even 3 times a month. When it pops out the pain is unbearable, and when it snaps back in the pain slowly dwindles away and is replaced by numbness. 5 or ten minutes later i can move it again, though it feels weird. By the next day it feels almost normal again...but there is another instance as well...Sometimes it happens so severe that i cannot move my shoulder without my muscles clenching in pain and it takes 3 to 5 or maybe even 6 days to fully recover... then it feels perfectly normal until it happens again... It has even happened in my sleep before as well. What is going on??