Girl-
you don't even know the half of it. In my situation to think I could be with a man for 3 years and some change, miscarriage (99% due to the fact that he did nothing but terrorize me my whole pregnancy), and getting his ex pregnant (and swearing it wasn't his child) and then some- I've known him since he was a stupid kid so I don't think anyone knows about this disappointment better than I.
Its rough but I think all three of us will make it through. He's my only boyfriend ever in life so its TWICE as hard. And the baby? Makes it even harder for me but I guess I have to push through somehow and you will too. Before you ever THINK of going back to him (if thats what truly in your heart) discern whether you really had any serious, serious problems. Be realistic with yourself- if he cheated on you 5+ times, getting back with him probably won't do anything but ruin your life, unimaginably. On the other hand, if it was something small that can be worked through, then go back to him, grab onto him and never look back.
And i've made it more times than I have fingers and toes and the obvious answer was staring me in the face. I truly do, with all my heart, believe he's my soulmate and the only one for me but if thats meant to be then he'll come back someday (maybe not if i'm not meant to be with him in this lifetime) and things will be better. But please be realistic with yourself- don't trick yourself into believing its not going to work if what he did was all in all a dealbreaker.
Only you can make that decision for yourself.
And before you open that can of worms be sure that this is what you want- its a hell of a lot harder once you REALLY start loving him and you have to cut it off because its breaking the both of you to pieces.
If you ever need a friendly ear, i'm here for you!