You won't officially have *G "status" on US until Tuesday nor will you be able to get automatic credit for the miles flown on Monday. See the "Transition to *A" thread over in the CO forum and specifically CO Insider's post about the 2-day "limbo" period between ST exit and *A entrance. For any *A flights flown on 10/25 & 10/26 you'll need to send the BPs into CO OnePass. Do not, and I repeat DO NOT, enter your DM number in the PNR if you want the miles on CO. If the DM number appears on the BP CO will not credit those miles. Once they are credited to DM there's no way to transfer them to OP.

For the flight on the 27th you should be able to give your OP number to an agent at the airport and your miles should credit automatically. Keep your BP just in case.