I am on birth control and I have been on

Patient: I am on birth control and I have been on for 4 months now on May 3rd I had unprotected sex some fluid got inside of me but not all. Around May 11-15 it was finals week and I took Adderall and I was extremely stressed from finals and My period was supposed to come the 19 it never came. I took two pregnancy test and they came back negative. What should I do is this normal ? I have also been exercising a lot lately like everyday.

Symptoms: No Symptoms

Doctor: