Informal Probability Question

Hey so I have a question about something that came up in my summer Intro to Statistics class. It has to deal with this idea where a Country follows a rule where couples are permitted to have up to 4 children or one son, whichever comes first (Up-to-4-Daughters-Rule.) And we are to assume that all the couples can have children and each child has a .5 chance of being male and a .5 chance of being female.

Then we're suppose to describe what happens to some proportions as this rule is set in place for a few generations.

70% males / 30% females

50% males / 50% females

40% males / 60% females

I don't know if I'm correct or not, but I think that there is a slight bias towards females when following this rule. Is this correct?

Any help will be appreciated!