Singapore to Shanghai exempted visa

Hello, I have a Canadian passeport but live in Singapore. I will be traveling from Singapore to Shanghai and will stay there 3 days. My hours will be below than the 144 hours, but I am not going to a other country after, I will come back to a Singapore. My 3 days in Shanghai are not transiting. I will not have my boarding pass yet for my flight back but I will have my ticket. I am eligible to a free visa?
Thank you