I had protected sex with with a girl on july 21 with a spermicidal condom, after coming inside her, we stopped and I noticed the condom was empty, and found a small hole about an inch down the shaft. About 10 minutes later after she had washed herself thoroughly and searched frantically, I found a large puddle of ejaculate on the bed about a foot away from where she was on the bed during sex. Just to be careful I urged her to take a Plan B contraception pill, which she did within about 24 hours. I know it takes only a little to get a girl pregnant, but it was a week after her period and she was no where close to ovulation. Do I have anything to worry about?