Have you ever made the biggest mistake in your life that you cant take back?

After being broken up with for about 4months by the guy I fell head over heels for.. I started going out and doing things i shouldn't of done because i was hurt and felt alone.. I seen him move on like 2 weeks after out break up and his new gf moved in a month after they were together on top of that she has a 4 year old son :/ that crushed my heart into Pisces.. so since our break up i started talking to guys.. not to try to get with them but to get my mind of my ex.. & one of the guys that i was Just friends with but began to talk to him but didn't really feel anything for... turns out that I got pregnant by him :( i know that it was a mistake and i should been smarted about not protecting myself but i was hurt at the time and didn't care.. wen i found out i was pregnant, abortion automatically crossed my mind :/ i mean im not with the guy & we have no kind of relationship... im working.. a full time student in college.. and not ready for a kid :( so i decided to keep the baby.. its sad because i got pregnant unintentionally and kill my baby is something i couldn't do :/ but before i messed around with that guy I met a great guy who is in the army.. hes the guy who actually has been their and showed me otherwise and who i seen a future with but not that im pregnant.. i can't be with him :( all my plans are ruined and im stuck with a guy whom i dnt love and loosing a good guy because im pregnant!.. it sucks.. and i hate being in this situation.. i guess making decisions based on anger cause consequences and i know because im facing them right now :( i wanna be happy .. i don't know what i should do about the army guy :( he dosen't know that im pregnant yet but hell find out eventually & im pretty sure he wouldn't wanna be with a pregnant girl :/ ppl make mistakes.. n sometimes those mistakes happened for a reason i guess :/ all because of a guy whom i fell for i chose to be stupid and make the wrong choice of messing around with a guy.. and look at were it led me to.. having a baby.. who has no fault :( and now that i actually found a good guy.. its like impossible because i have a baby in the way :(