I'm 15, and I've always had heavy periods. Half a year ago, my period started becoming really late. I went 2 months without, then 3 months without. On the 3 month period, it was EXTREMELY heavy. I was going through one tampon every 30 minutes to 1 hour. I started spotting 3 days ago, but I've never spotted before. The blood was extremely dark, almost a black color. The next day, there was no blood. I masturbate occasionally, and yesterday when I tried, I noticed that I started to full on bleed. I stopped right away and put a tampon in. 5 hours later I checked, and the tampon was almost 100% blood free. I thought maybe it was just kind of the last bit of blood and I had just forced it out of my body. After that, there was no blood whatsoever. Today, I tried to masturbate again. Same thing. I'm not experiencing any pain. I've researched this everywhere. I'm not pregnant, and I don't have any STI's. I'm severely worried. The blood only starts when something is inside of me. Someone please help me.