I’m on the pill but my periods are still regular, no pain and light

But my period was 7 weeks late I took 2 tests both negative, so I waited and it showed it’s face yesterday with very bad pain and brighter than usual?

(I’ve been at a festival this weekend so been drinking heavily)

I took my tampon out to change and I felt something strange and when I wiped it was this

I tried washing it to see if it was or not (silly I know) but it seemed to stay the same?

I know it’s probably nothing but I’ve never had a clot before.

P.s I also have an ovarian cyst if that could make a difference?

Apologies for the photos😳