You're just a tad over three weeks post-op. While your outsides are healing well (I had pain at my incision sites for quite a while after my surgery--especially the one in the rib area--was told that's where most of the manipulation took place.) your insides are far from healed and adjusted to the changes.
It's totally understandable that at this very early stage in your post-op recovery you will experience discomfort. Your stomach is not happy with you right now. It's been pulled and wrapped and stitched. Those changes will definitely take time to settle in and heal completely.
I was told by an experienced member here that it takes 6 months for the majority of the healing to take place, and a full year for the remainder.
It sounds like you're doing all the right things. You can get out and about
at this point...just remember (as I'm sure you do) that you've just had major surgery, and take it slow. Walking is good for your recovery, and getting active is important in regaining your strength.
Let me tell you that I coughed SEVERELY throughout my early post-op recovery period. It really HURT! I iced my painful incision, and hoped for the best. I was very worried that I would harm my repair, but what could I do? I'd also been told that my internal tissue was very fragile from the steroids I'd taken.
With all that, I still have an intact wrap. I don't think you have to worry a bit.
You're being very responsible and have a great attitude towards your recovery.
Keep up the great work, and try not to worry. It's just a normal part of healing.
If you ever have a concern, don't keep wondering...just call your surgeon and ask! That's what they're there for...you paid the big bucks for the surgery!
Take care and happy recovering!