Ok.... you didn't dismiss my point that pulling out is a form of birth control. You proved my point that it isn't as effective as other methods.

Yep, I 100% agree with your analysis in your 3rd paragraph. I am 100% at fault.

Yes, I have read up on effective birth control methods, which is why I know that pulling out is a form of birth control but isn't as effective as other methods. I never claimed to "know so much". I am fully aware that every woman's cycle is different, which is why I went into detail about her having a 28 day cycle (compared to other women with a 21 day cycle), the plan B or other factors may disrupt it leading to early ovulation etc.

Yep, I'm not going to contact her. 99% sure I'll never speak to her again (maybe in 3-4 weeks to make sure that she's not pregnant)