> Birth control (of all types) is responsible the bulk of the reduction in birth rate.

Birth control is a tool, which requires conscious thought. If you look at the UK: https://www.statista.com/statistics/281981/live-births-in-th...

You can clearly see two peaks in the last 40 years. Given that the last peak comes after liberalisation of the morning after pill, it breaks the correlation between availability and birth rate.

> end the lives of 73 million unborn per year

I'm assuming your joining 48hr contraceptive with <28 week abortion, otherwise those numbers would mean that (I'm assuming the USA) every woman in the USA alive would be having an abortion at least every two years. Given the number of clinics capable of carrying that out, I find that number difficult to prove.