If your going to birth in a hospital it is very unlikely that you wll have a physiological labour so many hinderances to a physiologic third stage.

So your saying uteruses dont contract properly or work properly without the injection well mine does .If it doesn't then give me the injection but I would rather try than just take it just in case
No I'm not saying that they don't contract properly or work properly without the injection - what I am saying is the injection ensures in most cases that it prevents PPH whereas it is a real risk in a physiological third stage.

Like I said, this is such a personal choice, but I can't see the benefit of waiting TBH - once my baby is out I'd rather take no risks