Pull out method is not sufficient birth control. Pre-cum can have viable sperm in it. While sperm can travel, it doesn't travel far. If it was left on labia or the like there's a possibility, but something like belly not as much. But pre-cum is the much bigger risk with pull out method
The pull out method is unfortunately never careful or safe, and particularly on a high chance fertility day there’s absolutely a chance of conceiving
There will be a chance that his precome could impregnate you but the semen he ejaculated outside of your body won’t have a chance to. But I don’t know the stats of how easy it is to get pregnant from precome!