Someone please help?!🙏🏻

I’m 36 days late for my period and I took a test when I was 1 and 8 days late but got a BFN

Symptoms -

Late period

Nausea

Back pain

Sore nipples

Head aches

Moody

Lost interest in sex

I know this might sound crazy but could the tests been wrong even tho I took one when I was 8 days late?