Help please I’m scared

So I know that spotting can sometimes be a side effect of birth control. But recently I have been having really bad spotting. Like I woke up this morning and my panties were covered in this black/brown “blood” I guess it would be. I cleaned up and didn’t get any for a bit but I just went to fiber myself and there was more under my nails. I’m worried. Is it supposed to be like this? Is something wrong?