Please help! I need to talk to someone!

I don't know how to say this for everyone on here is complete strangers. But I seriously need some help and advice. My hubby and I were TTC all of September. Well I got pregnant! But.... I also had a one night stand on September 14. May I also add that hubby and I had sex every night. He would cum in me and I would prop my legs as high as I could on the wall or pillows. I would also sleep like this and would t use the bathroom till I could no longer hold it. Anyways. The one night stand was an old friend. Tmi but I was on top and he pulled out way before he finished. The whole thing only lasted 30 seconds. Maybe. I told my hubby and now we're both worried. We're even contemplating abortion. What are the chances of it not being my hubby. Please no mean comments. We're working things out and I'm already a mess. If you can help please. I don't know what else to do. Thank you.