What Causes Umbilicus Discomfort With Bowel Habit Changes?

Hi, may I answer your health queries right now ? Please type your query here...I started having tenderness and discomfort in my navel and just below it...there have been slight changes in my bowel habits...but, nothing real noticeable. I do have a history of having an ectopic pregnancy and just ended my menstrual cycle yesterday. I did go to the VA ER today and without expressing the frustrating details...all they did was a urine test which was negative for HCG and WBCs to rule out what I suspected (either appendicitis or ectopic)...He did examine my abdomen and noted not other pain anywhere else and stated he felt no masses. Being a nurse myself and having discussed my symptoms with the doctor I work for...they should have at least done a blood test. The discomfort and tenderness is still there...and worse if I press around the area. My concern is what else should I look for at this point. I was trying to prevent a true emergency by trying to catch this early if it is something since I have others who depend on me. I really get sick and have a very high tolerance of pain...and this is new and I know something isn't right.....