Umm, what is this? (Tmi)

I've had very, very watery discharge all of yesterday and today, it was really heavy and while I was going to the bathroom is noticed that I had this random dot (about the size of a dime) of white cm, it couldn't have been there for more than 30 minutes but it looked all nasty and crusted on, like I've been wearing the same underwear for a week (I'm sorry for all the detail, I'm trying to explain it the best I can) I don't have any infections or anything, which is why it was strange. Anyone know what this could be?