No judgement, we all make mistakes.

I'm 20 and the father is 28. When the father and his girlfriend were having problems we hooked up. They have been together for a little over a year and she's more his age. We were friends mostly through text, we don't know eachother as well in person. About a month later I skipped a period and found out I was pregnant. He knows and we're both stressing. He says he loves his girlfriend and regrets what happened that night. As you can assume she doesn't know about our one night stand or me so he wants me to abort. A part of me wants to abort because im to young and I don't want to have to tell people I got knocked up in a one night stand but a part of me feels ashamed and selfish that I might be doing it for all the wrong reasons. The money is there so I'm not unfinancially prepared, it would just be hard considering I'm only 20 and still in college. I'm scared if I aport it will haunt me and I'll regret it but in the other hand we hardly know eachother enough to have a kid together and he's happy in his relationship and this could ruin it. I feel terrible about his relationship but a part of me really doesn't want to abort. I don't normally support abortion. Should I just lose contact with him and avoid telling him what I decide and have this baby without him knowing? Or would that be selfish and make it worse?