Maternity leave

Ann Marie • We have a 5 year old little boy and now we have our little girl on the way.. we gonna try one more time for one more boy. After the wedding...
I am completely lost when it come to maternity leave, do you have to turn in a doctors note or do you just tell then... I've had some pretty major complications and my boss said they can only accept a certain amount of doctors note.. Witch I don't think is right, it's my child your putting at risk I am not playing.