Hey..
I read that you need to make over US$150 before they pay you. That is the "minimum payment threshold".
If you do not make over 150, it is rolled over to the next month (and will keep rolling over) until you pass the threshold. Also you need to wait a full month.. So if you sold over $150 within the month of january - you will not get paid until the start of March. Not sure what happens in your first month -- ie if your app went live 15th September - do you need to wait until start of November or 15th November.
That said, I am not sure why your reports arent coming up? I have only just submitted an app (still in review) so I have no experience in this.... Just was curious too and found my answer on another site (quora). If you search "how much time does apple take to pay developers" it should show up.
Anyway congrats on the app. Goodluck.