Also, since the majority of fertilizations don’t result in a viable pregnancy or birth, Alabama’s child mortality rate is about to go through the roof. I’m going off of memory here, but I think that there’s only about a 50% chance of a successful implantation and after that there’s an additional 25% chance of miscarriage. And because those figures correlate with things like income, education, and nutrition - I think you see where I’m going.
I actually was looking it up today because I remembered that little factoid that miscarriages are more common than we think.
The problem is that it is impossible to get accurate data because it happens so early that most women don't know at all that they were technically pregnant at all. If anyone wants to research it more the term is chemical pregnancy. It is called that because once the sperm implants in an egg, the body starts producing the hormone that pregnancy tests look for. This means you can have a positive test without successful implantation. We probably really only know it exists because of women trying rigorously to get pregnant, as the symptoms of this type of miscarriage can easily be chalked up to a heavy period.
Basically any percentage is an estimation based on that data. But just another drop in the bucket of facts against their feelings, an embryo is not a person.
I think the only way to ensure we capture the number is to assume that all unprotected sex results in a pregnancy. To get the mortality rate we just subtract the number of births from the number of sexual liaisons.
When we’re doing medical monitoring of someone, we are pretty sure of what we’re looking at, just to be clear. There are definitive hormonal changes that can be observed as well as other symptoms, as you mention. It’s done particularly for people who are trying to get pregnant, and we extrapolate to the population scale using statistical analysis methods (adjusting for demographics and such).
And just to clarify, I’m not calling a failure to implant a miscarriage. I’m mixing it in with actual miscarriages in order to show that it’s ridiculous and that the “life begins at fertilization” crowd are as scientifically nonsensical as flat earthers. I am intentionally mixing them together, but wanted to be clear on that point.