A year ago or so I was sitting and all of a sudden a lump appeared on my low left ribcage. It felt like my rib was being pushed outwards, it felt kind of uncomfortable so i tired to push it back pressing it with my hand. It didn't cause any discomfort after that moment and neither so far, so I never really worried about it. However, my ribs are still uneven considering that the low left side of my ribcage sticks out a little more.
I've seen 3 doctors and all of them said it's normal to have uneven ribs, but what really bothers me is that none of them believed when I said the bone came out of the blue.
I have trouble breathing and sometimes cough triggered by exertion and laughing too hard which worsens during winter, but that has been happening since I was a kid (I'm 18). My grandmother has severe asthma so I always thought I had a not so bad asthma.