Please help pregnant and alone

[runningaway]

I really am panicing now, I awoke with a distirbing new OCD thought this morning and I am very distressed, I am 7 and a half months pregnant and I dont know what to do. I have pure O OCD but this thought has been going on in one way or another for like weeks and this morning took a new turn.

I got into a new relationship last year, it started in the Jan 2010. In the March I went away with a girlfriend, I was suffering with guilt from a previous break up and so often as I do self medicated on alcohol. Anyway on the last day I got so drunk I ended up sleeping with someone although my friend did not witness this. Although this mistake did make me realise I did actually want to be with my current partner.

I decided not to tell him as he is dead against cheating, my friend was not any the wiser, and the person lived in a different country, it was a one off. Also I had introduced my partner to my young daughter (he is a great step dad and she loves him) we were trying for a baby and I fell pregnant in august. We were really happy about this.

Now I am feeling guilt ALOT well about 12 hours a day everyday, it gets me up the night, now my OCD is always worse when pregnant but because this is a real thought IE not one of my made up in my head ones I dont know what to do for the best. I woke up this morning thinking what if this bloke (who is still in touch with my friend) finds out I am pregnant and thinks it is his? Despite it being conceived 5months after that holiday? I have no doubt the baby is my partners but what if the bloke thinks there is a chance it is, i dont know how clued up blokes are like this?

Anyway I guess my question is should I confess? If i do i am afraid I will loose my home, my daughter will loose another dad and he will never trust me again and he keeps saying stuff like once a cheat always a cheat but I can see no other way of getting around my thought, although if I do tell the OCD will keep on that he is going to leave me.

I dont know what to do this thought is driving me to despair now :(