so four weeks ago I was under the impression I wasn't pregnant through a blood test and then…

so four weeks ago I was under the impression I wasn't pregnant through a blood test and then yesterday I go to the Dr. and she didn't even test my blood for pregnancy so I still haven't had a menstrual cycle since 3/28 then on 6/9 I thought I started my menstrual cycle that night and it was gone by morning with a couple of days discharge. well now she wants to do another urine test and a pelvic ultrasound because she thinks I might be pregnant. I'm confused about my feeling and the way my Dr treats me