Hi, welcome to HCM I am Dr. Das
First of all, sperm is microscopic thing. It cannot be totally washed out during toilet. So, there is high chance of pregnancy
. In my opinion if you are within 72 hours go for emergency contraceptive
pills. If not,then wait for scheduled date of menstruation
, if missed then do a pregnancy kit test by using urine. That will show whether you are pregnant or not. But don't do the test before scheduled date of menstruation. That's all.