This may indeed be a suture or "stitch" abscess. This can sometimes happen when the absorbable suture that is used to close the incision emerges from the incision. Don't worry, this is a minor bump in the road and won't affect your overall outcome. You should talk to your surgeon about your concern. The best way to deal with it is to remove the suture completely and typically the area heals uneventfully thereafter.
Good luckMichael Morrissey, MD
From your photos and description, this may be a stitch abscess. If the stitch has fallen out, this wound should heal on its own over the next couple of days. If it doesn't let your surgeon know and have them see you. Try not to worry a stitch abscess usually will resolve without long term problems. Best wishes, Dr. Lepore.
Congratulations on having undergone the tummy tuck procedure; based on the photographs, I think that you have a very nice early outcome. Don't be surprised if you much happier with the decision to undergo tummy tuck surgery several months from now. Many patients undergoing this procedure will have significant emotional "ups and downs" around the time of surgery.
Your photograph and description are certainly consistent with an "stitch abscess" situation; these problems tend to be self-limited and should resolve on their own. Followup with your plastic surgeon for more accurate evaluation, advice and meaningful reassurance. Best wishes.