Pregnancy is always possible if you have been having sexual intercourse. It is much less likely, however, if you are using your birth control method correctly.
It is unclear what type of birth control you are using and how long you’ve been using it. Since you mentioned that you had unprotected sex near the end of December, I will assume that you just started a hormonal method of birth control sometime in January. For the first three months of hormonal birth control use, you can expect some menstrual irregularities until your body becomes used to the new hormone levels. Menstrual irregularities include bleeding or spotting between periods, a missed period, a change in the amount of flow, and a change in the amount of bleeding days.
Keep using your birth control method as directed. If you skip two periods in a row, take a pregnancy test just to be on the safe side.
8. February 2012
anonymous-qa