Should I massage to help my breast implants drop a little? 1 week post op, 300cc HP under muscle

You should follow your surgeon's advice, as massage is not always necessary. The purpose of breast massage after augmentation exercises is to keep the scar tissue that forms around your implants following surgery as soft and pliable as possible.You are still very early in your recovery and your breasts will settle in about three to four months. Please wait until then before assessing your results. 

The artificial volume immediately after breast augmentation is due to swelling. Massage particularly if it is vigorous can actually increased swelling. To my patients I give the advice that they should leave their breasts alone.

You can certainly massage your breast gently to move implants in and down as tolerated. It will help with softer capsule formation and possibly dropping/settling them down in dissected pocket.