Am I pregnant? My boyfriend and I had sex without

Patient: Am I pregnant? My boyfriend and I had sex without a condom but used the withdrawal method. The next morning I took the morning after pill to be safe. I have had 2 periods since unprotected sex and they came at the same time as they normally would however were slightly shorter than normal. I have had symptoms of slight nausea, lower back pain and exhaustion however I am a very nervous person. I have had 2 urine tests at the doctors and both have been negative. How likely is it that I could be pregnant?

Doctor: