My rib buldges out, what could cause it? it started after i had a baby? it is uncomfortable.

Maybe cartilage?: It's hard to imagine a bone moving out of place to form a bulge, but the front of the rib cage has a lot of cartilage. Cartilage is a little bit movable but may be more movable during pregnancy. Perhaps the cartilage and/or the junction of where it attaches to bone is inflamed (called costochondritis) and either moved a bit or just swelled up from the inflammation. A primary care doctor can check.