What is the term for this small hole on my scar? (Photos)

It looks like you may have some fat necrosis, which not uncommon.   You should see your plastic surgeon as soon as possible for an accurate diagnosis as well as wound treatment.  

This is delayed healing to your scar with granulation tissue in the wound. This can be treated with local care. 

It appears that you have some retained sutures.   I recommend an in-office examination as well as a detailed discussion with a surgeon who you are comfortable with.   Finally, make sure your surgeon is a Double-Board Certified Plastic Surgeon certified by the American Board of Plastic Surgery (ABPS), a member of the American Society of Plastic Surgery (ASPS), a member of the American Society of Aesthetic Plastic Surgery (ASAPS), and a fellow of the American College of Surgeons (FACS).Best,Dr. DesaiBeverly Hills Institute for Aesthetic Plastic SurgeryHarvard Educated, Beverly Hills & Miami Beach TrainedDouble Board-Certified Beverly Hills Plastic Surgeon

It is possibly a "retained stitch" which is where one of the dissolving stitches is taking too long and irritating the tissues like a pimple.  Get examined to know for sure.Best of luck!
Dr. SubbioBoard-Certified Plastic SurgeonNewtown Square/Philadelphia, PA

It appears that you had an augmentation mastopexy (combined with a breast lift), and you have some delayed healing. This can potentially become a more serious problem. I suggest a follow up with your surgeon. If you remain concerned and feel that your concerns have not been properly addressed, I suggest a second opinion with an experienced board eligible or bard certified plastic surgeon. A wound that is slow in healing in the setting of underlying breast implants can be a potential source of infection which can result in more serious complications. Best of luck to you.