He had on underwear? Rubbing against you is highly unlikely to be a way to get pregnant, sweetie. Usually a penis needs to enter your vagina. And that he had underwear on as well makes it really unrealistic. you sound close to having sex tough so you might want to buy some condoms just in case. Periods are funny in that you can all of a sudden have an off cycle. Out of nowhere you can be late. Things that cause that are illness, changes in routine, stress, weight gain or loss, etc.
Has your period come yet?