Help! This never happened before. My period isn't the same this month

So my period has ALWAYS been the same, always 1 or 2 days earlier than the date it was supposed to come, never ever late. I've never been pregnant. I am sexual active. This month since I didn't keep track of it on the app for couple months I didn't know what date it was supposed to come, but it came on Monday night. My period ALWAYS lasts 3-4 days and by the third or second day the blood is already brownish and almost gone i only get bright red little heavy flow on the first day one my period. It's always been like this. But on Monday night I started cramping and even though didn't know for sure what date my period was supposed to come I knew the cramps were those you get when your period is on the way. So I went to check and was right had gotten my period. This was Monday night which was very heavy flow like I would push a little and blood would come out of my vagina not much but heavy drips the toiled had so much blood the water was dark red in the middle but the blood coming out was very bright red. I wasn't on pain the cramps were mild and almost gone. I thought maybe because it was the first day. But never seen blood dripping out of my vagina that much like I saw that day. Anyways, Tuesday the flow was terribly heavy I was changing pads every couple hours (never happened to me b4) and the blood was really bright red. No pain or cramps. Wednesday I was expecting to be getting very little dark brownish blood cause that means it's ending but nope still getting heavy bright red blood, no pain whatsoever. Today(Thursday) the flow isn't heavy but I wipe and see bright red blood stains. It's been what about 4 days now? If I stick a tampon up there which I did today and take it out just to see the color it comes out covered in bright red blood. What does this mean? I have no pains, but I'm sexual active with 1 partner but we do not use any protection and I never took the pill. He always finished inside of me. Does this sound like a miscarriage?