Is This a Double Bubble? Is a double bubble painful? (photo)

This appears to be mild and in my experience most patients self correct with time. I typically have my patients wear a bra and cut out  a segment of it where I want the breast to expand (the lower pole in your case). If after a year it is still present you can consider fat grafting as an office procedure.

It might be a very minor double bubble. If your surgery was recent, it may well improve on its own.  Intermittent pain in the breasts is sometimes seen after breast augmentation.  Again, if your surgery was recent, it should improve with time.

I think a bit more time will probably solve this contour irregularity. You should consult with your plastic surgeon about the discomfort.

It looks as if your surgery was relatively recent.  In the area that is shown in the photo, the ridge may very well be your old crease under your breast which needed to be moved in order to accommodate your new implants.  Sometimes there is temporary swelling and bruising in this area that resolves over time.  If your surgery was some time ago, I would recommend an evaluation with your plastic surgeon to see if things can be improved.

Yes that is a very minor "double bubble" effect. I treat by riggotomies and fat grafting under local anesthesia.