WARNING: Picture is kind of graphic

So this thick, skin colored thing came out with my period yesterday and I've been freaking out ever since... It's really thick and has the exact same texture as skin (like touching the inside of your mouth kind of). Someone please tell me what the fuck this is. On top of that happening, Ive been having SEVERE cramps and back pain for the past 5 days. Usually on the first day of my period I have really bad cramps but they always go away after that first day. I just started taking the pill and this is my first period since taking it. Could that be the reason why I'm having such bad cramps for so long? Even so, what the fuck is this?! Help😰😰