How soon can i see if am pregant?

hi am 27 and my boyfriend cummed inside me on dec.23rd can i take a exam to see if am pregnant or not or how soon can i find out out I used First Response like 3 days earlier my missed period and it turned out positive. Which is correct explanation I am pregnant. And the last time I used this audition it was approaching almost a week before and it be correct too.
so my advice would be to keep on aleast 3days before you are suppose to start and use that check
I think they are well-mannered.
You should wait until you are belated with ur interval.