I'm 17 & recently started having sex without protection. I've done it a few times but the last time I did it my period was 6 days late & then I only bleed for 2 days but the bleeding was light then heavy then the next day I woke up and there wasn't a drop of blood on a clean pad. I was told it could have been implantation bleeding. I went to the doctor for a urnie test it came out negative. I took a regular home test it was negative. It's been almost 4 weeks since the last day of bleeding which was the day before Father's Day and this past week I been feeling stomach pain, sometimes I feel fat, some of my foods I use to love now disgust me in every way & I keep peeing every 10-15 mins.