Do I tell my boyfriend about the abortion?

My boyfriend cheated on me in january, went to a party and slept with some drunk . He lied to me about it for months, was a complete prick etc. I found out about it 3 onths later and obv left him. But my boyfriend had already lied to me once, i didn't believe anything he said to me anymore. I wanted to know all the details of him cheating, just so i could put my mind to rest. So i went on his facebook (he knows this) and spoke to the girl, and thinking she was talking to my boyfriend she admitted that he'd gotten her pregnant and that she'd had an abortion at 10 weeks. I never told my boyfriend this. Recently we got back together, wegot a lot of stuff sorted out and things are going good. Believe me, if he cheated again i'd **** him right off, I can do better. Thing is, i'd really like it if we stayed together and things worked out. So do i tell him he got the girl pregnant and she aborted it? He'll never find out of anyone else, the girl won't speak to him now and she lives half way across the country. No answers telling me to leave him please, already heard all that, just want to know if i should tel him or not. Thanks