hi
me and my boyfriend used the withdrawal system for almost a year without me getting pregnant but eventually we got carried away and he came in me.So its better to use protection.
The pull out method isnt always reliable as you can get sperm in pre ***.
So there isnt as much sperm so the chances of pregnancy are not as great, and it depends on the time of her cycle, but theres always a chance.
Use condoms or another form of b/c, or if she misses a period get a test.