Its really difficult to process and correct everything if they already gave you the contract so better for you to got your family status and then move here with or without your family.

It will be safe for you, otherwise.. long procedure will undertake and a lot of time and headache. Anyway, it is easy for the company once you are still outside of Qatar.

Try to negotiate everything you want before you come here and should be in Black & white.. don't trust what they say except what is written in your contract..

Goodluck..