The notion that teaching people that sex is not a recreational activity doesn't sit well with me at all - it suggests that it's a duty, something you do to procreate and that alone. So sex cannot be enjoyed by people - it is their duty to do it only when needed, and then, of course, the woman's duty to carry the baby for nine months and give birth to it.
My sex education at school was virtually non-existant (and this was in the late 2000s). We were basically told not to do it - no advice on contraception, abortions etc - just told not to have sex. Similar advice for drugs, drink and smoking, really. Little wonder that there's so many teenage pregnancies that have come out of that school.
There will always be daft couples who miss a Pill/forget a condom, or get drunk and go for it and regret it in the morning, or think "We've gotten away with it before, what the heck", and married couples who have a contraception failure, and women who are raped, and women who have a one-night stand and the father is nowhere to be seen. And there will be happily married couples expecting a much-wanted baby, where unfortunately either the baby has severe disabilities, or the mother is unwell. And there will be cases where it is just bad luck, a couple or a woman isn't ready for a baby yet, simple as that.
There will always be some women and couples who will feel able to go through with the pregnancy, and give birth, and take care of a baby. And there will always be some who won't. Some for whom it would be a great inconvenience, others for whom it could be the difference between life and death; good mental health and serious depression/PTSD, living and feeling that the only way out is suicide. And that is why it is imperative that we always, always, always make it possible and easily accessible for a woman to terminate a pregnancy.