If you're saying a positive blood test followed by a negative blood test, then unfortunately that sounds like you've had an early loss. Given the speed with which levels increase in the early weeks, blood tests three days apart should show a significantly stronger result on the second one, whether or not they give you numbers

I've always found it to be that I will get the negative test and then it can be up to a few days before the bleeding starts. Its always seemed extra cruel to me - leaves you hanging and hoping emotionally when you know logically that there is no hope.

Gentle hugs. Take care of yourself.