Me and my girlfriend had sex and I ejaculated in her vagina. She is on birth control. Can I still get her pregnant?

Great question! There is a risk of pregnancy any time semen enters the vagina. Most hormonal birth control methods are known to be at least 99% effective with perfect use. However, this means there are rare cases—less than 1%—when a hormonal method fails to prevent pregnancy.

It’s also important to realize that many people don’t use their hormonal methods perfectly. They take their pills late or forget to change their NuvaRing on the right day. When this happens, hormonal methods become less effective. With typical use, they prevent pregnancy about 92% of the time.

The risk of pregnancy from sex without a condom depends on which method your girlfriend is using and how well she is using it. Teen Clinic recommends using condoms 100% as a backup and to reduce the risk of infection. However, it’s your health!  Talk your partner about what will work best for the two of you. Consider visiting Teen Clinic to chat with a nurse if you’re not sure how to weigh the risks. Being sexually active requires a lot of responsibility; thanks for asking this important question!