Doctors Visit

So me and my man have been having sex like crazy this past month where I’m on birth control. We haven’t been using condoms cause he’s told me about his past and trying to have kids with his ex wife. They tried for three years, unprotected sex, and they where only able to have one kid. He tells me the likelihood of him getting me pregnant would be very rare. Now coming to the end of the month, tomorrow is my last day for my pills until the last week pills kick in. I’ve still not started my period. I’m worried and not worried at the same time. Im going to take a test in the morning to see but I went to the doctor Tuesday night and they drew blood to try and find out why my bellybutton was hurting, I told them I thought it was my appendix but they thought I was pregnant. Me and my bf waited around 45-50min to get the blood work back. When the nurse came in she said I was ready to leave and gave me a doctors excuse. Could blood work tell if I’m pregnant so close time for my period?