I'm 17 years old. I have irregular periods. I get them maybe every 2-3 months, not monthly. Never been on birth control. I weigh roughly 130 pounds and I however am sexually active. I'm a month and 16 days late on my period. But last week I started what I thought was my period?? It's brown blood, I've had a few quarter sizes brown blood clots. I'm going on a second week of whatever this is and the blood has turned into a pinkish red color, and it has been heavy at all! Is this a period, miscarriage.... HELP!