How could my stitch from my muscle repair TT pop so easily? I didn't cough very forceful and felt pop and pain after. 6 days PO

From your description it sounds as though your sutures in that area did not hold. I encourage you to return to your surgeon for an evaluation.  In the future use a pillow to brace against your abdomen for a cough, sneeze, or sometimes even laughing.  

Hello. Great question. Thank you for your pictures. I am sorry muscle difficulties. I will suggest you have a follow up appointment with your surgeon as he knows you best. If concerns persist, please consult with a board certified plastic surgeon for a detailed examination.

Thanks for your questions! Your abdominals are very strong muscles that are highly activated when coughing - depending on your fascial strength, it is possible to have sutures pop out of place. I encourage my patients to compress a small pillow into their abdomen when they cough to help prevent a lot of expansion and this can help the sutures stay in place. You may need to have these replaced depending on your healing and aesthetic progress; discuss with your surgeon around 6 weeks (keep in mind that tummy tucks can take up to a year to fully heal and show end results). With regards to your belly button, much depends on how your belly button was done. If it was grafted, markings could play a role. If it wasn't grafting (it was left attached to your abdominal wall and 'pulled through') then it should be in the anatomically correct position and may just look higher now that excess tissue isn't pulling it downwards. Best of luck!