Does Headache And Vomiting Indicate Pregnancy?

Hey, Me and my Girlfriend have not had sex but we do mess around, when we do mess around I do wear a condom and it has never broken. My girlfriend is on birth control but she had stopped taking it for a while because the pharmacy had messed up her prescription, and she was off of it for about a week. She started back up and when her period was to come it was about 3 days late? She has been getting a lot of headaches and they have caused her to throw up. She as not been throwing up constantly but maybe in the past 3 weeks she had thrown up about 4 times? Should I be worried?