Any change in your cycle, especially if you are not desiring pregnancy, can be a source of distress. This type of issue needs to be presented to a board certified OBGYN. While periods do generally stop when you get pregnant, some women experience a small amount of bleeding
or from the cervix that can look like menstrual bleeding. This happens because the cervix in a pregnant women bleeds more easily. If you are sexually active and you missed a period, then you should take a pregnancy test. The most common cause of a missed period is pregnancy. Other possible causes of missed periods is a syndrome called polycystic ovarian syndrome. This would be considered by your doctor
if you develop very irregular cycles. I think the first step you should take is to go to the grocery store and buy a home pregnancy test. These tests are inexpensive and are very sensitive. No matter what the result of the test, you should then schedule an appointment with your OBGYN. If you are pregnant, then you need pregnancy counseling from our doctor. If you are not pregnant, then perhaps a work-up for menstrual irregularity would be helpful in getting to the bottom of your issue. Good luck.