Hong Kong citizen from Australia entering China via Guangzhou

Hi all, I am confused by different information. I have visited Guangzhou twice in last 12 months without a visa. I used Hong Kong Identity Card and Entry Permit for Hong Kong citizen. However, someone told me I may be refused to enter without a visa. Very soon I will visit China via Guangzhou again. Not sure I can continue to fly over directly without visa like last two times, or I need a visa, or I go to Hong Kong then enter China from there?