Can anyone help?

So basically; AF arrived on Saturday, 2 days earlier than was predicted or around 13dpo I think. On Friday night I had some mild cramps throughout the night.

It was mostly brown staining and very light flow which is not usual for me. There was some reddish blood throughout the day and one red clot when I changed my tampon (sorry if TMI). I did have awful pains on my lower back on Saturday night and what felt like cramps in my low back.

Sunday and today= no blood at all. So I’ve basically had a 1 day period. My periods would be on an average of 3/4 days I’ve just taken a test although it’s 9.30pm and I can swear I can see a vvfl! Please someone confirm I’m not going mad or what is happening here!

Only symptoms to note are the occasional bout of Nausea and a constant dull headache.

If I didn’t have my ‘period’ I’d now be 15/16dpo.