What would you do if the person you love turn his back on you?

ok ive been dating this 29 yr old man for almost 2 yrs. wen we were six months in the relationship he told me he had a girlfriend but i still continued to date him. he got me pregnant twice a year after and i got a abortion now im pregnant again i want to keep tha baby but im really confused i let love get in the way i feel so stupid bc he has a girlfriend so once he told his girlfriend i was pregnant she said she wanted me to get rid of it and that she wanted him to pay for it. i thought about it and then i said yes but im really startin to feel bad bc im kinda attach to the baby already but i cant do this on my own imma need help im only 19 yrs old idk im just confused..he told me the other day that he wants to make things right with his girlfriend and he doesnt want the baby but remind he lead me on for two years and comforting me threw the pregnancy and all saying how much he wants the baby and telling me he loves me i just feel so stupid but deep down i still love him and cant stop thinking about him im even willing to share him with her...sometimes i think about jus getting the abortion and moving on but this will be my fourth one i kno i will never get over him...im deeply in love with him but i messed up bc i shouldnt have dealt with another womans man..please give me some advice...dont be mean dis is deep!!!