3 months post-op BA. I got 490cc moderate round Mentor silicone implants and they haven’t dropped. (photos)

I am sorry to hear about your concerns after breast augmentation surgery. Your plastic surgeon will be best resource when it comes to accurate assessment and advice.  
Generally speaking, there are many variables when it comes to the final appearance of breasts after breast augmentation/lifting surgery.  The main variables, in my opinion are your anatomic starting point, exactly how/where the breast implant pockets were dissected, the size/profile of breast implants utilized, and the "artistry" of the breast lifting performed.  Again, for this reason, your plastic surgeon will be your best resource.
 
Generally speaking, breast implants will "drop" into the pocket that was created during surgery. The rate of breast implant "settling" may depend on factors such as size of breast implant pocket dissected, tightness of the overlying skin/muscle layers, and size of breast implant utilized. Normally, it takes about 3-6 months (for some patients longer) to see the final result.  As the breast implants "settle", the lower breast poles will round out (generally improving shape), and the nipple/areola complexes will seem to sit higher on each breast mound.In situations where breast implants do not fully settle, revisionary breast surgery may be necessary. The operation usually indicated when breast implants are "riding too high" is called capsulotomy;  this operation involves incising the lower breast pole capsules and/or any tissue that is preventing the breast implant from settling  symmetrically.
 
 Best wishes. 

Can sometimes take 4 to 8 months postoperatively to see the end results from breast augmentation. However, one must also be prepared that sometimes an ideal outcome does not occur. If you feel there has been no, discuss this with your plastic surgeon. Continue to follow his or her advice. An honest discussion and treatment plan can be achieved. It is possible that implant repositioning may be necessary in the distant future.

Thank you for your question. You are still in the healing process. Keep in mind it is not uncommon to have swelling. Breasts may not heal at the same rate, causing one breast to appear different than the other. It can take up to 12 weeks for the implants to settle and you to see the final result. Follow up with your board certified surgeon to address your concern. Good luck!