I am planning a trip to Asia and I will be in Shanghai for 3 days. My itinerary is as follows:

May 4th: NYC -> Hong Kong
May 12th: Hong Kong -> Pudong airport
May 15th: Pudong airport -> NYC

Do I need a visa to visit this city? I read that there are both 72 hour and 144 hour travel exemptions for Visa's if I am passing through SH on the way to a 3rd destination. Does my trip quality for this exemption? Also, does SH fall under the 72 hour or 144 hour travel exemption? I read recently that SH is now under the 144 hour travel exemption.