Dear Neha,
In a Philippine setting, and I believe in other countries as well, the basic principles of the employment system (not to mention "Generally Accepted Principles") apply regardless of the stipulated substance of the contract, whether written, implied, or the employment status quo. The Labor Standards (Government Implementing Guidelines) were created for the benefits of the employees (maternity, accident, wages, and all other fringe benefits), whether stated or not stated.
An EMPLOYMENT CONTRACT, by definition, is an instrument of convergence between the employer and the employee and does not always follow the settlement unless substantiated by the provisions in accordance with the sovereign law. For example, even if your maternity benefits are not stipulated in the contract and even if you have agreed to the terms, the labor law trends may impose preemptive measures voidable in your favor.
You should always remember that the principles of the employment system shall always be viewed through the prism of tripartition.
Regards,
Vlademir