Regular BC plan B hack

So my husband and I used withdrawal when I was at the peak of my fertile window.  By the time I  realized this all pharmacies were closed so my friend gave me 8 of her normal birth control pills. According to a chart I saw on Princeton.edu site you can take 4 normal pills within 24 hours of intercourse and 4 more 12 hours after the first dose.  I did this in hopes that it will work. We have a one year old and do want another just not right now.  I just wanted to know if anyone had tried this "hack," and has it worked for you? Or what anyone's experiences are with plan b or other emergency contraception. I know it can throw off your cycle.  Any insight is much appreciated. Thx