The perfect use stats of pull out are actually really good. The problem is a lot of blokes aren't able to do it properly, and they warn you off it so so much as a teenager because realistically a young lad who is inexperienced isn't probably going to be able to do it right.
If you've got a bloke whose practised and knows what he's doing then the odds of getting pregnant using it are really very low, especially if he doesn't leak first which some men do and physically cannot help or even know it's happening.
Compare that to some teenage experiences I had where the guys only managed to pull out halfway through ejaculation, by which time the other half had already got where it needed to be!!! All these types of 'pull out' are counted into its success rates, and that's why it comes out so low.
Pull out VS TTC are totally different ways of having sex.
More to the point, I think you need to talk to your bf about TTC, as it seems like you are hoping for a pull out fail to get pregnant, and since he knows what he's doing that seems unlikely. I do appreciate that trying to have a baby seems a lot scarier than ending up with a happy accident when you were already basically ready, but most of us don't fall into that camp. Seems like half end up pregnant and unprepared and have a scary start and the other half of us have to take the blind plunge into trying for a baby and trusting we feel ready to do it.
It would be lovely if everyone fell accidently pregnant around the exact time they started to feel ready, but it doesn't seem to happen often.