Positive urine test but negative blood test

A bit of background: 43, partner is 53, we had our little bundle of joy in December 2019 with a single round of

<a href="https://glowing.com/glow-fertility-program">IVF</a>

after trying for 2 years and 1 chemical pregnancy at 5 weeks.

Now, I had my first period on Dec 15, not too worried in taking precautions, no period yet, took an expired pregnancy test at home on Jan 28 and bang strong positive. Ok maybe because it was expired. Went to get a new pack, tested the same day and again strong positive. Went then straight to the doctors for blood and today I got the call the results are negative.

I tested then again today and still strong positive and no sign of AF.

What’s going on??

First top it’s the expired one, then Thursday and today (Saturday) test 🤷🏻‍♀️

I had full blood screen in November and it was all normal. No signs of UTI either.