My Boyfriend cheated and I'm Pregnant

I'm about to be 17 and I am 3 months pregnant. My boyfriend is in jail and serving 2 months. A couple days after he got locked up, I found out he had been lying to me. He was saying he was staying at a GUY friend's that I knew. I found out by 4 different people that he had been picking up this girl,I specifically told him to stay away from, and taking her every where and staying at her house. When he called I confronted him and he admitted it, apologized, and started crying and pleading. Well the next day I found out he had sex with her 3 Times(including oral for her) and had told her we were broke up, they also was unprotected. This girl is not a normal one, she is the get-around-girl. Meaning, not only if she had a disease, he would have it down there and in his mouth. Those days that he cheated on me he had been coming to me, not only risking my life, but my baby's too. I despise him so much for this, but I would hate to have an abortion then find out later that it was the only kid I could have had. It just seems like my luck, to have miscarriages or complications. The decision I want to make, is to have the baby, but take all his rights as a legal father, away. I know its wrong, but if he didnt care to think about the baby when he was havin sex with her, then what's the problem. Besides, Idon't want my child around him and the diseases he'll catch if he continues. Help me make up my mind........TornDecision!!!