Okay ex g/f help! please read im confused?

Im dating someone, and she thinks she might be pregant, Well i've been talking to my ex alot lately and shes still in love with me we dated like 4 years back and we broke up, and im still in love with her, i dont kno what to do or how to pick, my g/f i have now all we do is fight it's so hard but i have fallin in love with her too so.. what do i do?