About halfway through my pregnancy I kept feeling this lump by my left rib and when I told my doctor…

About halfway through my pregnancy I kept feeling this lump by my left rib and when I told my doctor about it, she felt it but said that it was just the baby pushing something and thats what I felt. I told her I felt sharp pains on there and when I laid on my stomach it felt like there was something there, she always said it was most likely nothing. When I went to my ultrasounds, she checked but there was nothing she could see. I felt it all through the rest of my pregnancy and now that I'm not pregnant anymore I can still feel it! I still thought I had to wait for my body to return to normal, but I've given it almost 6 weeks now and I can still feel that lump, it hurts when I lay on that side or when I'm feeding the baby and leaning on it I get sharp poking pains, right now I'm just sitting down and I'm getting the sharp pains. My appt is next Monday and I'm letting her know but I'm getting so worried now of what could be wrong!