What Are The Chances Of Pregnancy Despite Missing Few Birth Control Pills?

I have been taking Gildess 1.5/30 for a few months now. I was starting my pack on Thursdays. After i finished my pack, I was supposed to start my new pack again on thursday but decided to wait until Sunday so I wouldnt get confused with the days of the week. Therefore, technically I didnt take a pill Thursday, Friday, or Saturday. (The first 3 of a new pack). What are my chances of pregnancy because of missing those?