Spotting after missed/late period

Hi

I was 22 days late and took pregnancy tests and they were coming up negative.

Today I thought my period had started up, however, it’s just very light spotting and I have pretty bad period cramps. Worse than usual. The blood looks quite fresh as well.

I feel like it must be way too late for implantation bleeding and I should definitely be showing a positive pregnancy test anyway if that was the case.

I’m really confused and wondered if anyone has experiences this and what happened. It takes weeks to get a doctors appointment at the moment so thought I’d ask whilst I wait

Thanks