Hello, everyone.

My girlfriend and I have some odd circumstances in regards to this post. Pretty much:

We were drinking a bit then started messing around. We ended up having anal sex for roughly 20 secs max. I am curious as to the possibilities of pregnancy (I know anal sex alone will not get you pregnant, but some other events could "theoretically" do it).

* The last time I ejaculated was roughly 36 hours prior to us messing around. In which case, I urinated 15 times.
* I never ejaculated during any of it. We messed around for a while before anal actually happened.
* I did not touch her vagina at all with my penis--it was, I made sure, all anal.
* My girlfriend was on the last few days of her period.

Now, theoretically, if there had been sperm in my pre-cum it could swim over from any liquid around her vagina, swim through the uterus, and chill for at max a week.

I am seeking information/feedback about the chances of any pregnancy developing from this. All the theoretical events just give a chance of it; however, I am seeking the real world possibilities. I am holding the belief that it is 99.9% chance that we are worrying for nothing.

Can I get some input from people, please? Again, please not the hardcore theoretical, but the real-world chances. Any input will be greatly appreciated.

Edit: I did not have a condom on. It was just a stupid thing to do on both our parts.

Thank you in advance.