Negative blood test but positive HPT

Sim

I had my last periods on 13th July but my cycles have been extremely irregular n I ovulated around 18th august I assume( because of my symptoms n temp). On 24th august I had diluted pink spotting which lasted for 2days without clots and cramps.

My HPT before this bleeding were all negative while all HPT from 27th august onwards were positive

I got my blood work done on 30th august and 6th sept but both reported negative for pregnancy.

I have symptoms of pregnancy like nausea occasionally, fatigue n headache etc.

these were my tests from 5th sept which came positive within 30seconds of testing.

Did anyone have a similar experience and ended up being pregnant with a negative blood report?