Is it normal to get stabs of pain in my chest/ribs?

I've gone to my general practitioner about it and she said it was just normal for teenagers. (I'm 18 now but this has been happening fairly commonly for at least 6 years) However, it f-ing hurts. I can't tell if it's my muscles or my ribs or my lung or nerves, but it's almost like I get stabbed with a needle every once in a while. More common when I've been sitting in one position for a while, especially hunched up, but it happens under random circumstances too. I have a family friend who is about 25 who says he's had it for a long time too. I usually just have to wait out the pain. Moving makes it worse. rip me I guess