I ejaculated inside my gf and she took the plan b pill within an hour. we had safe sex again shortly after will this affect the effectiveness of pill?

What is "safe sex"?: If you used a condom the first time, then Plan B shouldn't be necessary. Since she took plan b, i assume you didn't use a condom. Don't forget that condoms also lower one's risk for catching/giving sexually transmitted diseases & infections in addition to lowering risk for pregnancy. Plan b is a hormonal method for emergency contraception that should not be affected by other birth control pills.