You should see doctor if pain increases.
I have studied your case.
I want to ask you if you are feeling pain in same leg in which injection was given. It can be possibility that your injection might have touch nerves in thigh. I would suggest you to take pregabalin
and methylcobal tablet for pain relief.
Also take warm water shower on thigh and leg. If your pain is in other leg than you do not need to be worried. Take brufen
for two days. Your pain will be better.
Also to prevent such pain in future I would recommend you to take salt in your diet a little more and also take calcium daily.