What do you think the chances are?

Nicole
Hello everyone 🙂 I hope you're all having a wonderful day. So my question is : What do you think the chances of pregnancy are, if my boyfriend and I use condoms, and I have him pull out?
Might I also add, I am not on the pill or any other form of birth control, we just always use condoms, but only using condoms makes me worry (I worry a lot) 
So, what do you guys think? Also, I usually wait until the week or so before my period to have sex, since that seems to be the safest time to do so. I will appreciate any input you have! Thank you all