What Are The Chances Of Getting Pregnant After Taking Levonorgestrel?

i'd a sex with the used of condom yesterday around 5 pm. Then i'm so worried if i may get pregnant until i bought a capsule pf Levonorgestrel from the pharmacy nearby n took it at about 2 pm today as the pharmacist says this emergancy pill may help to avoid pregnancy if i take it within 72 hours.. Is there still any possibilties for me to get pregnant??