Question

Cyce 29 days last period was on the 15  of feb but I'm in regular 
I had unprotected sex on March 1st prior to this I missed three doses of my BC pill n on March 8th I started spotting first it was brown then light pink  is lasted until the 13 and then just stopped I was supposed to get my period today cause I'm on birth control but I didn't get it could I be pregnant I experienced nausea today n I never do  Could this be just a complication from missing doses and my period is late cause of that I scheduled an appointment with my OB but I'm curious and inpatient wondering