What Causes Delayed Periods With Brown Discharge?

have been on birth control for 2 month now. And last month a week before my period came i had brown discharge for a 2 days and a week after my period came on May 12. Then on June 10 i stated to have brown discharge and for a week now and i am 4 days late. I have be cramping once in the blue and I usually irregular. I have been having unprotected sex and this week since i was stressing i forgot to take my pill once. is it possible that I am pregnant?