My gf took a home pregnancy test on the 24th day of her cycle because the last times she got her period was on the 24th day before that it was the 25th day and before that it was the 24th, so she figured the 24th. The test said not pregnant. It's been three days and she hasn't got her period yet. The thing is we didn't have sex... we were just lying on my bed naked and the fluid that comes out of my penis touched her vagina (it wasn't sperm). Should we be worried?