Can Pregnancy Occur Despite Taking I-Pill?

i had make out a lot of times the last whole month though he didnt entered inside me. 2 days ago i lost my virginity but he didnt ejaculated inside me and yesterday i took an i-pill too for being on a safer side. now i think i am delay on my periods with a week or more but i dont remember my periods date exactly. what could be the reason for the delay. is this due to pregnancy. m worried. please advice.