My girlfriend and I had sex but I didn’t ejaculate but I may have had semen on my penis. Today she got her period (thankfully). Is there a chance her period could only last for a day and somehow be pregnant? Does having a period 100% mean she is not pregnant?

Teenage couple with pregnancy test

If a woman has vaginal bleeding, it does not 100% mean that she is not pregnant, but it is less likely. Many women can have periods that come more or less often, last a different number of days, or are heavier or lighter. The average time between women’s periods is about 21-45 days. During the first few months of pregnancy, some women can also have vaginal bleeding that looks like a regular period, or is lighter or shorter than usual. Many women who are pregnant will also have other symptoms such as nausea, sore breasts, and/ or cramping that does not come with their usual periods. For this reason, it’s very important for any women with an irregular period to talk to a health care provider to find out what is causing it. It’s also important for you and your partner to use a reliable birth control method such as condoms and birth control pills to decrease the chances of your partner getting pregnant if that is not something that you both are currently planning. Remember: there is a risk for pregnancy any time the penis is in the vagina, even if the male does not ejaculate.