My Experinace.
1) Make sure she really is pregnant... you have no idea out of the 44 years I have been on this planet how many times I have heard girls tell friends they were pregnant and it was theirs.. and they never were pregnant. I have had it happen to me a few times and the girl was never pregnant.. Sometimes girls really think they are because sometimes they get so stressed they will miss a few periods, then add on to that girls sometimes tend to eat more when they are stressed.. so stress can cause a girl to miss a few months AND gain wait.. and then they think they are pregnant.
And sometimes they know they are not, but they just want to put the guy through hell.
2) If she is pregnant, make sure it is yours.. if you two have been split up long enough where you are with someone else. how do you know it is yours..
If you detemine she really is pregnant, AND it is yours.. man up and take care of your repsonsabilities... If she wants to abort, support her, if she doesnt want to abort, support her. And if you are not married to someone else, sit down and think if you could make it work with the mother.
Oh and. and to add.. it is NOT all your fault.. she apparently consented so it is a 50/50 deal.. so dont be getting all down on yourself.. you are not the first guy in this canoe and I promies you that you wont be the last...
So yeah, you should have worn protection, but she could have been on birth control, she could have went down and got a morning after pill.. lots of things SHE could have done that you couldnt have done... so dont let ANYONE make you feel like it is all your fault and dont back down from that stance..