If I go with bigger implants will my scar continue to move up in my breast? (Photos)

I am sorry to hear about your concerns regarding the scars. Communicate these concerns directly with your plastic surgeon; he/she will likely be able to hide the scars in the inframammry folds. There will likely be several options available to you moving forward. Best wishes.

Going with larger implants will make the scars less apparent, as the larger implant will cause your breast to overhang and cover the current scars more. Since your implants are already in place and settled down, larger implants should also not affect where the scar is on your breast, unless your surgeon intentionally lowers the breast fold more, which should not be necessary if upsizing a reasonable amount. 

I am sorry to hear of your dissatisfaction.  Your scar should end up fading nicely to a small white line.  A revision surgery with larger implants will create a slightly larger scar but it shouldn't be much more than what you have.  Also if your breasts are larger then the scar will sit more in your inframammary fold so hopefully you will be happier with that.  Best of luck to you.