It is possible to get pregnant even if the sperm is not ejaculated into the vagina. This is because the sperm is very wandering and very small, invisible to the naked eye, and even a very small number of sperm can enter the vagina through the hymenal opening of the vulva. If an egg happens to mature and is discharged, the sperm and egg will unite and form a fertilized egg, which will then pass through the fallopian tube to the uterine cavity where it will implant in the endometrium. This is why it is possible for a virgin to get pregnant, but the probability of this happening is very low. If your period is delayed for more than a week, you should consider if you are pregnant. You can use a pregnancy test or take a blood test for HCG.