Rabies vaccine. Any over dose reaction?

2 days earlier i had a little dog nail scratch so today i visited to a doctor and he prescribed me to take 3 doses of Abhay rab vaccine........ Earlier i have taken 2 abhay rab doses in Last year December and again 2 abhay rab doses in October 2018. And in 2017 I have taken 5 abhyar rab vaccine...In total till now I have taken around 25 anti rabies vaccine in laat 8-9 years... So my question is- 1.Today the doctor doesn't inject the vaccine in my hand or arm instead he injected in my back side in  buttock/bums but earlier all the vaccine i have taken in arm...So is it good to take in buttock?? Will the vaccine will work?I am confused. 2. As i have taken so much vaccine so will be their any over dose reaction??? Please ans both questions.. Thanks