Hi Lestyls,
You can go onto a medical aid (and I would advise it...) but they will not cover your pregnancy related doctors appointments or the birth of the baby. However your baby will then be covered from birth, so if there is any complications with baby and a NICU stay is needed, that will be covered.
It is worth it as they will cover you for normal gp visits for flu etc and baby if there is a problem with baby after the birth, the hospital can require that you put down around R55 000 before they admit baby to NICU. If you have already paid cash for the birth, that is not the kind of money that you want to fork out...
Good luck with the rest of your pregnancy and enjoy it!!!