Hi Ribbler,Welcome to the Healing Well 
Wrapped Club! I think you mean you had surgery on August 15th.
To answer your question about shoulder pain...yes, yes, yes. It's very normal, and can cause more pain than the incisions themselves. I found that walking helped alleviate the pain. The more I walked, the less pain I had.
Here's a link to my early recovery journal. It might provide you with an idea of another person's experience:
https://www.healingwell.com/community/default.aspx?f=45&m=2183443
Your surgeon gave you a 6 week note, and that's the one you ought to listen to. I'm sure that time frame took into consideration your line of work. It's very important to avoid strenuous work during the early recovery period. If by "light duty" your supervisor means paperwork, you could probably manage to go earlier. But if it means bending and packing, or lifting of any kind, stay home and recover. People who go back to desk jobs after two or three weeks always tell us that they wish they'd taken longer, but they manage.
Glad you've joined us. Be sure to ask any questions as they come up. We'll do the best we can to answer them!
Happy healing!
Denise