Negative tests but still pregnant!?

2nd had to be it, haha

I'm now 11 days overdue. In the first week, I tested negative twice. A few days ago I tested again and got two positive results. Just now at the GP's office, though, it was negative again. They did take a blood sample though, since I do have pregnancy symptoms.
Feeling tired and unsure like this.

@sandra which tests are positive? I'd get a blood test done then you'll have certainty