Really confused about condom statistics

It was my first time 2 weeks ago. We used a condom properly, no tears or breaks, but he did not pull out. Planned Parenthood says proper use of a condom is 98% effective at preventing pregnancy. Is the 2% from breaking even though it was used properly? Can any sperm get through if it didn’t break? I’ve read many comments about women saying they got pregnant by using condoms properly and BC so I’m a bit confused. Thanks for the help.