I had sexual intercourse with my girlfriend on wednesday and she lost her virginity and her menstruation was due yesterday and she still hasn't gotten her period. I do not want to be graphic but I used a condom and pulled out before I ejaculated into the condom. I did not ejaculate before that and I urined before to clear and sperm in my urethra. Does losing her virginity change her menstrual cycle? Is that why it hasn't come yet?