Pills or barrier methods
like condoms and rings , the choice is yours but chances of failure are more with barrier methods.Condom can tear off very often and ring is a very cumbersome procedure and sometimes doesn't fit properly and can cause failure.
Pills are having more efficacy but certain side effects with long term use and if you forget for 2 days then the chances of failure are more.
So it will be better to use barrier methods like condom + an emergency contraception
like I pill
or pill 72 , Ecee
pill etc within 72 hrs of unprotected intercourse
Please do not buy any medicine without asking a doctor especially intramuscular injections , they might cause irregular bleeding and prolonged amenorhoea.