I havnt got my menstral period for about 3 months this has happened be for but i just don't understand why i am not taking any birth control i am not currently sexually active and don't seem to carry any sign of being pregnant

There : There are other reasons besides pregnancy that can cause a woman to miss a period such as: stress, diet, excessive exercise or a hormone imbalance such as with a thyroid disorder or poly cystic ovarian syndrome. Also, if you are within 2 years of starting your period, it is very typical to have an irregular cycle. If you continue to not have your period, you should contact your doctor.