Thoughts? Chemical pregnancy?

So I took a pregnancy test yesterday as I was 14dpo and I had missed my period. Both tests came back positive, one after the other..

This morning, I took another 2 and they also came back positive..

this afternoon, I had extreme backache and my downstairs area was really painful… now I’ve received red blood and my af has arrived… no cramping though…

Was this a chemical pregnancy? If it wasn’t, why was the pregnancy tests saying it was positive? I’m so confused and upset right now?! 😩😞