It is very hard, but not impossible for the sperm drops to enter the vagina, reach the cervix, pass the uterus and reach the tubes where the actual conception occurs. The vaginal environment is usually hostile for the spermatozoids. So the penis helps by ejaculating deep in the vagina, thus shortening the time they spend in the vagina.


If her menstrual cycle is about 28 days and the period lasts about 7 days, then she might have been in her ovulating days. You might want to wait until the expected time for her next period to exclude the pregnancy.