Sammy, I had a home birth (although not unassisted - I think you are very brave for going this route!!!), but in order to smooth things over in the event of complications and having to transfer, I did pre bed booking at the local private hospital. This meant (although I had no intention of using the booking) that had I had to transfer the hospital would have had my info on file (back up gynae, med aid details) which would assist my husband with admission. It also meant that the booking fee entitled me to the 3d scan (which I wanted) as well as the birth immunisations. The day after James was born I went through to the hospital where I collected my rhogam prescription for my midwife to administer (I'm o neg) and get the first 2 immunisations in maternity ward. The nurses gave me the immunisation card.
However if you dont want t go that route, all you need to do is take your baby down to one of your clinics after you give birth. (Government clinics), say you had a "unexpectedly quick delivery" they will check baby out, give the injections and give you a road to health card. You need the road to heath card in order to register your babys birth at home affairs and get a birth certificate. Hope that helps.