Sir/mam, me and my girlfriend had sex on 23 August.. it was unprotected sex but I manage not ejaculate inside her vagina, but I think that some amount could possibly droped in her vagina, so I askd her to take I pill, but she forget to take it, and later naw after 20 days she told me that her periods are delay.. she was expecting her periods on 5th of September, but it isn't ye, and she is not feeling well . Also vomit once and feelng weak, so is there is chance of pregnancy, and if it is then how to prevent it.. because we are not ready to get married and have babby

When her period is two weeks late she can take a pregnancy test following the directions on the box exactly. Unfortunately, there is no way to prevent pregnancy now. If she finds that she is pregnant abortion is an option as is adoption.

There is sperm in the fluids, that men have during sex. So you did not have to finishing in her, for her to become pregnant.

It is possible that she could be.

She will need to take a pregnancy test, normally first thing in the morning , as soon as she wakes up, be sure to follow directions, carefully.

If she is pregnant, then she already is pregnant, and no way to prevent.

There is abortions and adoption as other options.

Then why have unprotected sex if " we are not ready to get married and have babby". That's a good way to have a "babby".