I went through the same kind of panic! See if you still have the eml from when you registered, and check the date. You probably have one or two days to go is all. You'll turn adult on the same day of the month you registered last month, so if today is the 18th for you and you registered on the 19th... well, you're not far off! You can also check the options screen and make sure 'play as fawn' isn't checked, but if that option doesn't even exist, then it means you just haven't hit adult quite yet!

Hang in there! It'll happen!