Dear K33K33,

If it has been four months since you've had sex, and you've had three periods, you cannot be pregnant. It isn't possible to have a period and be pregnant. It is possible to be pregnant and have vaginal bleeding that may seem to be a period — but this is very rare. The only way a woman can be sure if she is pregnant or not is to take a pregnancy test.

There are other reasons besides pregnancy why girls might have a late or missed period. These reasons include stress, illness, a diet that's too low in fat, changes in sleep patterns or exercise, or just a menstrual pattern that hasn't become regular yet. It can take a while for a young woman's body to adjust to hormone changes and begin to "run" smoothly and regularly. She might have a light flow or a heavy flow, the length of the flow may vary, or her periods might be late. She might even skip some months. Most likely a young woman's periods and cycles will become more regular as she grows older.

Women who miss three or more periods should see a clinician who can determine why she's missing her periods, and prescribe treatment, if necessary. To make an appointment at a Planned Parenthood health center, call 1-800-230-PLAN.

Hope this information helps!

Take care,

teenwire.com^® Editors

This column is for informational purposes only and is not intended to constitute medical advice, diagnosis, or treatment. If you have a medical problem, please call toll-free 1-800-230-PLAN for an appointment with the Planned Parenthood health center nearest you.