weekly payout question

Hi, my weekly payment was set to sent out the 15th but now it has switched and says it will be sent on the 22nd instead? Is that just a glitch? I was really banking on getting paid on the 15th and it would be a real bummer as I got bills to pay.
Haha. I do have another question, how do I change my username on here? I want to change it to the one I have on the main site which is XgtWrath.