Precum + the pill?

My boyfriend and I recently decided to stop using condoms. I’ve been on the combo pill for about 1.5 years and I’ve never missed a pill (I’ve taken it late but never gone a full 24hrs without one). We always pull out now but I know there is a chance of pregnancy from precum. Also, I never get my period because my birth control only has 2 placebo days.

What are the chances of me becoming pregnant? I just need to ease my mind.