Hugs to you hun, sounds like you need them. Can you talk to your mum about this? Will she be supportive?
I really don't think getting back together with your partner sounds like a good idea since the reasons you broke up will still be there. I guess you need to weigh up your options and decide what is best for YOU in this situation and how you feel about everything. Its a lot of hard decisions to make I am afraid, perhaps some sort of counselling with someone used to dealing with these sitautions?
As for bubs you need to go and see your GP ASAP so you can get checked out, there are many of us who have done things we shouldn't have done before we knew we were pg so please don't beat yourself up over it, you cannot change the past just work on the future!
There are very many wise and beautiful women on this site who will be able to offer more advice than me so you have come to the right place.