I am 16 years old, a Junior in high school. Me and my boyfriend had unprotected sex once, about a week after my last period. WE stopped, because we realized what we were doing and didnt want it to happen. Last week i was extremely moody and i figured it was my period. I was supposed to have my period about 3 days ago, but nothing happened. I started worrying myself sick about whether or not i was pregnant. I havent had alot of symptoms. I have been eating as i normally do, i have not gained weight. I dont feel tired or anything else..just moody. Today i was talking about it to one of my friends and i went to the bathroom and started bleeding. I had been reading alot and i figure that either i was stressing about it so much that it came a few days late, or i miscalculated. Or it was implantation bleeding. It wasn't a pink or brownish like ive read, but it wasnt DARK red either. It was just normal red. Im also having cramps. Could this be implantation bleeding or a regular period?