Help...

So I got a positive opk on 25/01/21

AF arrived 11/02/21

Only lasted a few days they normally last 7 days every single cycle, took a test the day after AF had finished and got a faint line with diluted urine!

I don’t understand how I got a second line when my period just finished I was thinking implantation bleeding but I think it was too heavy for it to be implantation?

It’s so faint but 100% there!