Hello I Am A Girl Of 25 . I Do

hello I am a girl of 25 . i do not know that complete sex is done or not. it means that penis is reached to deeply inside or not. but he loose his liquid in my vagina. i did pregnancy detection card for that n i got negative result . my periods are irregular. this thing is done before 20 hrs .what should i do ? i will be pregnant or not? is there need to take i-pill tablet or not?? pls help me as soon as possible.