Congratulations!! Same thing happened here. I didn't want to get pregnant till next year, when I'd lost all the weight and maintained it for a while. Even then dh and I were going back and forth if we even wanted another one. A month before finding out, I had a touch of baby fever but quickly dismissed it because of my goals. We're doing the natural planning method, I obviously (now we know) Ovulated a week later then I should've where we had 2 days of unprotected s*x.
I was in complete shock and denial until I heard the heartbeat 2 weeks ago. My dh on the other hand was in shock in the beginning but is now thrilled. When I heard the heartbeat, I just melted and cried like a baby. It was beautiful. Its all about watching what I eat so that I don't fall into my old habits during pregnancy.
My midwife told me, instead of seeing this as defeat, to instead see in as another journey and adventure in my weight loss. To take what I learned and tweek it to have a more healthy pregnancy and a more healthier post-pregnancy outcome. That is my new challenge.
Wishing you all the best!