Probability of getting pregnant with no birth control?

Hi all. I have been taking birth control (Yasmin) for about 5 years now. I have recently stopped it but continue having sex with my boyfriend. He always pulls out and has never mistakenly ejaculated inside me, but we don’t use any other form of contraceptive. I just want to know the probability of getting pregnant by precum is? Or if anyone has any similar experiences like this? I’m honestly very anxious about it and I can’t find any good sources about it anywhere.