An ex-coworker (a nice girl) with whom I had sex with exactly 1 time (and haven't seen since), recently had a baby. When I heard the news I started doing some math. Luckily I know that exact date of the one night stand and the baby's date of birth. She gave birth 295 days after we had sex. Is that within the time frame of possibility. I definitely used a condom, and she says that the father is now out of denial...but I don't know...seems a little too close for comfort for me.