Is this a symmastia? Can this be fixed? (Photo)

Yes, you have it despite looking good a few days out. I guess it is possible for this to occur from a tight fitting bra, but I wouldn't have expected it. Regardless, a specialized bra will not help at this point (and perhaps at any point); you will need surgery. This would consist of with repair of the current pocket with capsular tightening and mesh reinforcement, or my preference for symmastia, creation of a new subpectoral pocket.

Dear Maria569,
based on your photos, it doesn't look like you have symmastia. I understand your concern. However, without a proper assessment, it would be difficult to determine what went wrong. It is best that you visit your plastic surgeon for further assessment or ask for a second opinion. Only after a thorough examination, you can get proper recommendations and advice.
Daniel Barrett, MDCertified, American Board of Plastic SurgeryMember, American Society of Plastic SurgeryMember, American Society of Aesthetic Plastic Surgery

Hi Maria,
I'm sorry to hear the trouble you've been having! When a person experiences implant related symmastia, it's usually because the implants (profile and volume) don't fit the patient. The manufacturers show the base diameter for each implant and that should line up with your natural breast base diameter. If the diameter is larger than your natural base diameter, the implant will have nowhere else to go except medial or sometimes it will end up going laterally.
I wish you the best in your search for treatment!
-Dr. Nik

Dear Maria,
I do believe you have symmastia starting. I would have advised using a smaller implant rather than going larger. The width of these implants appears to be too wide which causes/contributes to this problem.
Best wishes!

Your implants are too large and wide for your frame. I would suggest going back down in size to fit your base better. The medial pockets can be tightened.

You are correct, this is a symmastia. It appears that both implants are crossing the midline, but the right breast more so. This requires a revision procedure with plication (suturing) of the medial cleavage area and possibly reducing the size of the implants.

You do have early symmastia
You should be wearing a symmastia bra
If it does not resolve surgery may be required