No Problem I understand the raw emotions. Our worst was when friends announced their pregnancy, due the day after ours would have been. A lot of crying and some harsh words were said by us to each other then. ps I was pregnant again 3 weeks later.
So... I am not a science person but I am a teacher, so going into lecture mode. Sorry if I am repeating what you already know, and what I am about to say is a little simplistic, but it is the best way we understood it.
Each human has 46 Chromosomes. 23 from mum, 23 from dad.
We get our 46 when the sperm and egg meet and they combine.
But how do we get a cell (Sperm and egg) to only hold only 23 chromosomes? (told you lecture mode)
The cells that will become the sperm and egg copies its 46 chromosomes. So in one cell you have 2 lots of DNA, adding up to 92 chromosomes.
The cell then breaks up the 92 chromosomes into 4 parts (23 chromosomes).
These four parts are then placed inside a new cell (the egg or sperm)
So that is all well and good, as long as it works.
What happens ALL THE TIME is that the breaking up of the 92 chromosomes doesn't go well.
Think about when you photocopy something. Sometimes the copy is perfect, other times, there are little mistakes, or blurs, or faded spots.
Instead of making four lots of 23, sometimes the chromosomes don't separate properly. So in one cell you have 24, and (as a consequence) the other cell has 22. Or you might have 25 and 21.
So there are two eggs (OR TWO SPERM) that won't work from the moment they are created. And this happens A LOT. so you might have thousands of sperm (there are way more sperm then eggs) and hundreds of eggs that don't have the right number of chromosomes.
So when the sperm and egg meet. One might have 23 Chromosomes, and the other 24. so the baby will have 47.
In some cases that doesn't mean much. It is how people with Downs Syndrome are the way they are. And there are a few other conditions where the person has an extra Chromosome with varying degrees of consequences.
But it really depends on which Chromosome has been either duplicated or left out. In many cases the foetus doesn't have the right DNA to actually grow into a baby, or if it did, it would be severely handicapped or not live long.
Your body realises this and takes steps. Harsh but true. I hate to admit it, no matter how horrible the MC was, the situation was preferable to having lost it at birth, to late in the pregnancy. My heart breaks for parents who have had to endure that torture.
For me, understanding that either my DH's sperm or my egg could have been the one with the wrong number of chromosomes, took some of the guilt off of just me, and also that it was never going to happen from conception meant that I personally did not do something that caused it. especially as there is SO much out there about what you, as the mother, should do and eat or else, it is hard not to take some of that on board.
I hope that all makes sense, and sorry if I sound a little like I am lecturing you. Force of habit.
Again, my DH grieved along with me and in his own way. The doctors made a point of checking in with him, to ensure was ok as well.
Hope this helps