I had brown vaginal discharge for about 3 days instead of my period, followed by being extremely fatigued and moderately nauseous. i take birth control and havent had any problems before. could i be pregnant?

Maybe not, but: It can be hard to tell if a woman is pregnant because some of the symptoms seen in early pregnancy can also happen in non-pregnant women. A home urine pregnancy test gives a reliable result by 3 weeks after sex (3 weeks after when conception might have occurred), or 1 week after missing a withdrawal period. An Ob-Gyn doctor can evaluate any persistent or worrisome symptoms.