Bleeding during sex

This has happened twice now.
Yes i am due on my period in the next few days.
But last night me an my partner had sex. There was a lot of blood. Bright red.
But today its gone, nothing.
I have Fibroids an cycts on my overies.
Is it connected? or was it my period?
Because im due on did sex just make some come away earlier?

But i thought you had an hormone change an then that triggers your period!!!

Im on the pill.

Has this happened to anyone else?

Thanks