Hello, and I hope I can help you today. Pregnancy symptoms very widely between women, and symptoms normally associated with pregnancy like breast tenderness, spotting, feeling bloated, and nausea can all be associated with irregular menstrual cycles as well as pregnancy. Furthermore, when you first conceive your uterus is only about the size of a chicken egg and is situated low in your pelvis, so any pain near your ribs would be unrelated to pregnancy. If you were not yet late for your menstrual period when you performed a pregnancy test, you may have had something called a chemical pregnancy. A chemical pregnancy results when conception occurs, but the few cells that grew together when your egg was fertilized do not implant in the uterus and are washed out. This is why your test looked weakly positive and then may have become negative. So, at this time, after three negative tests, I think you can be reassured that you are not pregnant. If you are trying to conceive, I suggest waiting for a full normal menstrual cycle to arrive and then only performing a pregnancy test if your period is late next time. I hope I was able to adequately answer your question today and that my advice was helpful. Best wishes, Dr. Brown