I was really surprised when I read your experience. generally, salary is paid monthly and pay date should be stipulated in contract, like"paid at the end of each month". Is the school you mentioned in dalian a public school or private school?

comparatively, public school will not give you highest salary, but the working environment is relaxed,may some time they delay payment for soemdays( due to official reporting, signature,making forms...), but they will pay you. and their salary counting is not detailed in every teaching hour, that is to say they maybe pay you more than expected according to contract described, of course that does not happen to every one.

you may require 30days probation as the content of contract,this will give your chance to know the school. the negative is that some eployer maybe terminate contracts in their favour.