If you have not used birth control or a contraceptive device and your periods have been regular up until February, there is a chance you are pregnant. However, certain stressors such as excessive exercise or dieting can decrease the frequency of your periods. The first test most doctors perform when a woman misses her period is a pregnancy test. Therefore, taking a pregnancy test either with store-bought urine tests or in a doctor’s office can help give you a definitive answer.