Blood bubble? TMI warning

So this is the first time I've posted but I am kinda freaked out.

Yesterday I was laying down and something felt "off" down there. Best way to describe it was like a bubble or a small gush I went to the bathroom and I was completely covered in blood.

I had my last cycle on Aug 6th, at least I'm pretty sure it was, mine has been super light lately. Even though mine are irregular due to PCOS, 20 days is still too short. I'd been having in between light bleeding, but nothing like this. Last time I had in between light bleeding it was a medium-large cyst (16mm) so I had made a doctor's appt last week for Monday (27th).

I have no fever or pain anywhere. Could it have been a cyst, fibroid, possibly early miscarriage?