If you havea longer cycle then it may take a little while longer for your two get a positive test. When I had my first, we weren't trying to get pg, but my period was slightly late and I had so many symptoms, but I never got a single +ve test. I even needed two blood tests to confirm it as the first one wasn't conclusie. I was close to 6 weeks pg before I had a confirmation of pg. I'm confused though as to why your Dr would rahter give you meds to speed up a bleed when she knows that you are actively trying to become pg. SHe should have ordered another blood test to give the HCG a chance to get high enough to detect.