Hello doctor,,,i had unprotected sex with my girlfriend on 19/4/2016 and 23/4/2016,,,she was going to have periods on 25/4/2016 but she is not getting?

Pregnancy concern: If she missed her period after having unprotected sex, then she should take a pregnancy test. Home pregnancy tests are usually good enough to detect pregnancy at the first day of the missed menstrual cycle. If neg, check again in a week if still no bleeding. If you two do not desire to start a family, it would be good to talk about contraception together, then see a doctor to start something.