I am 16 years old. I had unprotected sex about 3 months ago. My period usually comes every 30-35 days. I still have not had my period. And I have a small "bump" under my naval. And I have wierd/ uncomfortable feelings in my stomach, but its not cramps. In June me and my boyfriend thought I was pregnant because I was gaining weight only on my stomach just like I am right now,but i, took a test and it came back negative. Then thaat same day we went riding four wheelers and hit a bump and my stomach had a peircing pain went through the lower part of my stomach and that night I had my period but it was lighter than ever and we had unprotected sex again... And in July I had my period, and then unprotected sex again. And so far I have not had my period. What are the chances I could be pregnant, or what could be wrong with me?