Your menstrual cycle only increases and decreases the probability of getting pregnant at different times in your cycle. There is no time that it isn't possible. In other words, any time you have unprotected sex it is possible to get pregnant. At this point you should take a pregnancy test. Pay attention to the instructions to make sure enough time has passed to insure it will be accurate.
Anybody that is sexually active should clearly understand the information in the nine links at the bottom of the Planned Parenthood teenage web page:
http://www.plannedparenthood.org/info-for-teens/pregnancy/am-pregnant-33831.asp
