HELP! Positive at home tests but negative blood test?!

I have been taking tests over the past couple of days and they are getting darker. This morning I had a faint positive on FRER. It was faint but pink and both my husband and sister saw it (and my husband never sees any lines that I see.) it looked exactly like the first one I took when I found out with my last child. I was supposed to start my period today but never started that either. Went to the doctor and got a basic yes or no blood test done and it said negative. How does this happen? I feel crazy...is something wrong with me?