Going to Shanghai, Hong Kong, and Macau

Hello,

I will be landing in Shanghai (PVG) on January 12, 2018 at 5:30pm. Then I will be departing to HKG from PVG at 9:30am. This will be about 136 hours in Shanghai first.

Then I will stay in Hong Kong from 11:50am on January 18 to January 23rd. From what I hear, Hong Kong has a free 90 day stay for United States passport holders.

Afterward, I will be taking a boat to Macau to stay between the 21st and 23rd. Macau also has a free 30 day stay for United States passport holders. On January 23rd 4:00pm, I will take a plane from Macau (MFM) to go back to Shanghai (PVG) and then I have to wait 3 hours before transferring to another plane, to fly back to (LAX).

Will I need to get a visa in this scenario, or should I be fine without not getting one?