Hi girls I have a birth control question. Hope I can get some feedback. To start I am currently on the pill

Jolessa- (Levonorgestrel and Ethinyl Estradiol

This is my first time taking any birth control, for my first time my doctor recommended me this one. It's been 3 weeks since I started taking it and today I just started my 4th week. I usually get my periods every 18/19 of every month. But with this pill I supposed to have a period every 3 months something like the shot. So far I could say I haven't had any bad symptoms everything has been great so far until today I noticed a thumb sized dark color blood clot come out and it freaked me out a bit of course since this had never happened to me. And I'm wondering is this normal due to the fact I was supposed to get my period this upcoming week in a few days? Does this happen? I am quite confused and I would like some feedback from you girls.

By the way for all those who respond TYSM! ❤️