Gynae bill taken of my savings instead of MB

I have contacted Momentum when I suspected I was pregnant (around 4weeks or so) the lady advised me that I should wait atleast until I am 8weeks to book an appointment with my Gynae so that the maternity benefit can kick in. So we get a list of gynaes on the network make our appointment and wait anxiously to meet our baby for the time! Now I get a claim from the gynae that was taken of my savings instead of MB. I called the MB department and spoke to a VERY rude Victoria who said there isnt anything she can do I should have registered first then gone to the gynae, But my question is how do you know how far along are you or if infact you are pregnant if you do not visit the gynae. The lady I called initially said that the gynae