Had unprotected sex today. my partner did not ejaculate in me however i took plan b a few minutes after it happened. did i take the pill properly?

Sooner the better: The sooner you take Plan B the more likely it is to be effective. Sounds like you were WELL within the recommended time frame so, yes, you took the pill correctly. Plan B should not be your method of birth control as a general practice though and I would certainly recommend you see your Gyn to discuss your best options (AND 100% condom use to reduce STI risk)