My girlfriend and I had penetrative sex with a condom and that was only for a minute, afterwards I took it out. Later, I ejaculated on top of her and it only got on her stomach area and lining of her underwear. It was 2 days after her period, she usually has a consistent cycle of 30 days. She is 3-4 days late for her period and we are extremely concerned although it seems like its impossible for what we did for her to be pregnant. Keep in mind she was wearing underwear as I ejaculated. She is very worried that a drop or two got on the area of the vagina. What do you think?