Hello !! I Am 23 And Had Sex With My

Hello !! I am 23 and had sex with my boyfriend on the 31st day of my last period..while having sex i was not on my periods..although he used condom and we have checked properly if there is any leakage or not (and it was absolutely fine, no leakage was there) still i am afraid if any traces are left in my vagina..24 hours has passed.should i take an emergency contraceptive? Do ECs have side effects? Please help