US to Shanghai to HongKong then US

I was born in Hong Kong and have a valid HK Identity card and an U.S. Passport. I want to fly from U.S. (Nov 5th) to Shanghai (Nov 6th) to attend for a friend's wedding then fly out (Nov 9th) from Shanghai to Hong Kong. I will fly from Hong Kong to U.S. a couple weeks later. Do I see any additional requirements or issues to enjoy the "72-hour Visa-free Transit " like other foreigners?