The auto system said that visa fee bill was generated 24th. It has been a week and I haven't received it yet. Should I be worried? Also, they said that my AOS fee was process and I sent the I-864 a week ago but haven't received it yet either (following short-cuts). Did I send it too soon?

call the operator and ask what forms have been mailed to you up to this date. they should tell you what and the date generated. the fee bill may not show up for 2 weeks (seems to take about 10 days for me to get things from NVC on the west coast)

I received IV bill 8 days after been generated, so you will get it some of these days.

it all depend if your paper work stuck in mail room or not.
some time operator said it generate and send that according to computer when the info input. operator doesn't know the exact date stamp on the letter from the mailroom when it actually send

You sent them out too soon. You have to wait for the bill is generated.