I had it for the first time in my life . I am 27 years old.?

and he could hardly insert 1/4th of his (please pardon me for the crude language). The very next day my periods were due that means i had it just one day before my monthly cycle. He tried it twice and both the times he came outside. Now its been 3 days that my periods are delayed. Though, my periods are normally delayed by 2-3 days. How much is it possible that I am pregnant?