Since I had my son 2 weeks ago I've been having this weird stabbing pain behind my belly button. It gets really bad if I walk and now when I carry the baby. In the beginning I just chalked it up to typical pains of having a 5th baby but this feels different. There's also a little swelling. Best way to describe it, is it looks like when your belly button pertrudes when pregnant, except it's kinda on one side and it's tender to touch. What is this? should I take a trip to my doc before my 6 weeks appt?