Pregnant even after negative blood test?

Hi- I got a positive opk on 12/1 but am unsure of when I ovulated as I had spotting on 12/4 (and I thought it was implantation but it seems more likely that it was ovulation related?) I have NEVER had spotting before like that so I was very hopeful- anyway I jumped the gun and did a blood pregnancy test yesterday which was negative. My doc said maybe it was just too early but I don’t know if she was saying that to let me down gently or not. She said if I don’t get my period next week I should retest.

My question is has anyone actually gotten a negative blood test and still been pregnant?? Seems like a long shot and yet I really feel like I am...