PLS HELP TMI

Ok so I’m 16 and Friday I started having light kinda bad cramps and I started having this brown discharge from my pussy. I assumed it was from the first birth control shot I got on October 30th. I also missed my period last month onna 7th and I thought it was cus of the birth control too. But I was laying down later on that night and I just felt really wet and I put my finger down there and when I pulled it back but there was a lot of blood so I got up and went to the bathroom and i peed and wiped and when I did this was onna toilet paper so I was like “wtf” and I called my cousin and she was shook and I called my grandma into the room and she said I had to wait till tomorrow to set up a gynecologist appointment so I just cleaned up and layed back in bed Bc I was cramping really bad... later that night it was like 11 I felt like I was soaking so I got up and went to the bathroom again and this time there was blood running down my legs. And I went to wipe it off but we ain’t have no toliet paper so I pulled my pants up and went to go get sum and when I did I felt something cold in my pants leg and when I pulled them back down this was there??? Does anybody know what’s happening??? I gotta gynecologist appointment on wensday and I wanna know what to expect thanks💙