Supra-pubic swelling after tummy tuck.
Only three things can cause swelling; blood, serum, or pus. With prior treatment for cellulitis, you may have developed an abscess. Please have this investigated and treated. The antibiotics can only do so much if the space is not drained. I hope you have been back to see your surgeon.
You should see your surgeon ASAP
There are many reasons for having pain, and you should see your doctor as soon as possible for an examination. You could have a late seroma, or fluid collection that has become infected and can cause pain and swelling. This typically drains dependently and could pool in the suprapubic area. It would need to be drained with a needle and possibly an ultrasound. You could also develop an abscess if left for too long.
Emergence of pubic pain for weeks after abdominoplasty should be reported to your surgeon.
You don't provide enough information for a valuable opinion. If you had a previous infection in our developing swelling and pain in the pubic area it would be best to check with your surgeon.