BFP but faint.

So on Saturday I tested with Free Response and clear blue digital and they both can back positive. The free response had pretty dark lines too, even though I must have just become pregnant. Went to doctors today and at first doctor said I wasn’t pregnant but nurse came back and told him that it was faint positive. He then made me go get my blood work done and came again to tell me that I was definitely pregnant. Do you think it just took longer at doctors since I didn’t give them a large sample?