On Sunday (12/9/12) my girlfriend and were having some fun time. We didn't have sex but she grinded me (rubbed her vag up and down my shaft). I wasn't wearing a condom and there was quite a bit of precum. Her most fertile days (so says some calculations on a website) were Tuesday and Wednesday. Her next period is around the 26th. I had not ejaculated in a day or two and I had peed and hour before (and of course more than that the day before) what are the chances of her getting pregnant if the precum got ON the outside of her vagina? Just needed some reassurance. She took some water afterwards and washed her vagina some just as a precaution. Please answer this as accurately and quickly as possible! Thanks!

The chances are pretty small, but not nonexistent.

Going on the internet to determine her fertile days will not be accurate. In order to determine when she's ovulating she'll need to monitor her basal temperature for at least 6 months. Online apps go by the majority of women with a 28 day cycle. Most women don't follow the norm.

Peeing before sex, washing the vagina after sex, or any of the other things you've done, will not prevent pregnancy. Even birth control isn't 100% effective. If the sperm even gets near the vaginal opening it's in and on it's way long before you can wash it away. Remember all it takes is one, and they're microscopic.

She'll have to wait until her next period is due. If its 2 weeks late then test using first morning urine. If that test is negative then wait until the next period is due and test again if it's missed, or get a blood test.