birth control and period clots?

so i’ve been on the pill for three months now, i started my “period” today and it’s been pretty light (as expected)

but when i was about to have a shower i noticed a massive blood clot the size of my thumb, i didn’t feel it come out (tmi) and it’s kinda worrying me

as for history, my first “pill period” was heavy but that’s because i started taking the pill mid cycle, and that’s what happens.

my second pill period was skipped because i took two packets back to back

and i’m just really worried because i’ve never had blood clots that big before, usually tiny

anyone know what this could be?

thanks! x