Collection account questions?

I know that I have had a few things go to collections but they aren't listed on my credit report. Most of them are payday loans that I got online but I can't remember what company they came from and I've moved a few times since the charges occurred. How can I find out exactly how many bills I have in collections and how much I need to pay? I really want to clear up 100% of my debt but it's hard when I don't know where to go or who to pay.