They have discontinued giving the two-day shipping as a AzMom prime benefit when you order diapers/subscribe and save items. You can either get the 30% off (w/subscribe and save + amazon mom discount) and free regular shipping, OR you can get 15% off (w/subscribe and save) + free two-day shipping (w/amazon mom).
I opted for the 30% off and slow shipping since I could wait the week.