if you are in the uk then you can leave 11 weeks prior to your due date....
if you are signed off sick then that wil continue but if you are off sick during the 4 weeks prior to your due date with a pregnancy related illness then your work can automatically start your maternity leave for you...
an excellent place to look to work out your maternity benefit as in your pay, your entitlement etc where employers go to calculate it is....
http://smpcalculator.inlandrevenue.gov.uk/SMP1.aspx
your money etc depends on how long you have been employed by your current employer....you have to be working for your employer for 26 weeks prior to the 15th week the baby is due...
My god my memory still works and brain is fully working tonight lol
h x