Tearing pain in upper abdomen? (Photo)

Thank you for your pictures and questions. It looks like you have a nice result. If you have recently returned to activity and this is causing discomfort, I would suggest that you are likely doing too much too soon. Back down on activity and be more gradual with the return to activity. Some anti-inflammatory medications might help and I would also encourage you to call your PS and schedule an appointment to be evaluated. Best of luck!

Recent or sudden pain after resuming exercise is not uncommon but I would recommend giving your body some time to rest before restarting your exercise regimen.
Once the pain has resolved with rest, introduce your way back into exercise slowly. If you start feeling pain again, don't push it. You will know what your body can handle and it is important to listen to those indicators.
Rest. Rest. Rest.
It's my opinion that the bead you're putting in your belly button is not causing any damage and is unrelated to the pain you're experiencing. 
Address these concerns with your Plastic Surgeon at your next follow up appointment. 

Pain in the left upper ab area after restarting exercising is a sign that you probably pulled some scar tissue from doing too much too soon.  I let my patients start core strengthening about 8 weeks after a tummy tuck. I make them start slowly, at about 10% of their prior routine. If they experience pain then they are asked to decrease their exercise for a few days prior to starting again. I don't think it related to your belly button. Check in with your surgeon to be sure.