First let me say that you are not alone! I know several women that have had experiences similar to what you are going through, myself included. I am not a medical professional but I can tell you that I had similar issues, random periods, large clots, lots of pain, etc. After years of avoiding the OB/GYN out of fear I went in and was diagnosed with Polycystic Ovarian Syndrome or PCOS. In a nutshell I have cysts on my ovaries, and I don't always ovulate. I makes my periods awful. I'm not saying that you have this, but you do need to see a gynecologist. Female problems, in my opinion, do not go away on their own, and you need to see a medical professional for help. A gynecologist will likely suggest birth control to regulate your periods, and I can tell u from experience that it helps. Don't be afraid, you are not alone! Good luck!