Gf due for period this week , its not here. gf has moodiness, no cramping and says birth control might set it back a day. should we be worried?

Family planning.: Any time you have unprotected sex, there is a chance of becoming pregnant, even if your GF is on birth control. BCs certainly help reduce pregnancy a lot, but they are not 100% effective. If you don't want to become parents, or she does not want an abortion, then you should use a condom every time you have sex. She can use a urine pregnancy test to check if she is pregnant.