Possible miscarriage?

Hi! So im on the pill for the 3rd time and on my 3rd pack. I have the one where you only get your period 4x a year. So I started the last row (sugar pills?) on Monday and it’s now Thursday. I assumed my period would start today but for the past week I’ve noticed some signs of spotting everyday, some days worse than others, and then today I started my period and had really bad cramping in my uterus area and also my back. But then (so sorry tmi) when I went to the bathroom I noticed a huge lumpy tissue that had passed and that has NEVER happened to me. I normally barely passed much tissue at all but I’ve never seen anything like this and it was about thumb sized and like mentioned before lumpy and firm. Now I’m not the best at taking the pill at the same time everyday but I never have missed a pill but was having unprotected sex with my now ex so if anyone could give me some input that’d be great because I’m very confused and worried.