How long till I can get a revision for bigger implants? (photo)

I think you result is very good.You certainly can get a consultation now and have your new implants place in a little over one month. 

Typically, it's best to wait 6 to 12 months depending on the reason for #revision.  Matters such as sagging or drooping  and size change will not improve with time. As with all cosmetic surgery, results will be rewarding if expectations are realistic. With any surgical procedure, there are some #risks which your doctor will discuss with you during your #consultation.

Bigger
implants will not solve your problem. A larger implant will make them hang even
lower than they are already.Your
problem it not lack of volume but poor positioning.You would benefit from a simultaneous
lift.Most women refuse breast lifts
because of the ugly vertical scars associated with lollipop or boat anchor
incisions.I recommend a new technique
called Breast Augmentation with Mini Ultimate Breast Lift™.Using only a circumareola incision it is
possible to reshape your breast tissue creating upper pole fullness, elevate
them higher on the chest wall and more medial to increase your cleavage.Aligning the areola, breast tissue and
implant over the bony prominence of the chest wall maximizes anterior
projection with a minimal size implant.The implants you have currently will be adequate but need to be
repositioned and your breast tissue needs to be repositioned as well.This should have be done at the time of your
first operation. Best Wishes,Gary Horndeski, M.D.

I do agree that your implants have dropped and you have a nice shape. However, to minimize the chance for a complication such as capsular contracture due to scar tissue, I would wait a minimum of 3 months before increasing breast size, and ideally 6 months. At that point I agree, that to make a meaningful change in size you need to go up at least 150cc.  You do have to remember that the risk of bottoming out does go up, but your frame looks like you would be fine with larger implants.

As stated before, there is a period of time you should wait before proceeding with any type of revision implant surgery.  You are young, and so your implants may continue to settle for another couple of months, thus appearing "bigger."  In the meantime, your body is creating a layer of scar around your implants called the "capsule."  A soft capsule means a soft implant and good result.  Doing anything to jeopardize that is foolish.  So you let the capsule mature for at least 6 months before another surgery.  If you do another surgery, add more than just 120cc or I think you'll be underwhelmed with the change.  Hopefully, you'll realize that you have a great result with where you are now a live a little before "upgrading."  Good luck.