I have to go every week for the next 5 weeks, but earliest I can go is 30th Sep for my first injection... Then I got a text from the doctors this morning saying after the 5 weeks are up I need injections every 4 months for the rest of my life....

Surely they would need to wait to see the results of any blood test after the 5 week course then maybe in 4 months time before saying I need them for the rest of my life? I will be bringing this up with the doctor on the 30th.