As a peer alluded to, that's going to be for some ideal demographic in their twenties (probably early), hitting ovulation perfectly. Age changes things dramatically:
"Women younger than 30 have about a 20 percent chance of getting pregnant naturally each month. By age 40, the chance of pregnancy is about five percent each month." [1]
Things like IVF do not dramatically change the odds either. They're better of course, but it's far from guaranteed - it's still just a rather expensive roll of the dice.
Then on top of all of this, having children later greatly increases the chances of miscarriage, developmental issues (like Down syndrome) and so on.
Life's brutal here - you're in a race against time, yet the later you start the longer it takes, and the harder it becomes.
N=1 anecdata here, but... My wife and I got pregnant -- both times -- during the first month of trying. We were mid-30s, myself being 3 years older than she is, and my wife was old enough at the time of conception to have had a "geriatric uterus" and our first pregnancy, spontaneous fraternal twins, was considered "high-risk" out of the gate because of her age.
> Things like IVF do not dramatically change the odds either. They're better of course, but it's far from guaranteed - it's still just a rather expensive roll of the dice.
Sadly, literally all of our peers who were trying and having kids in the same demographic as us, +/- a few years, struggled hard and most needed fertility treatments. At least 2-3 of them were never able to conceive, despite the expensive and time-consuming treatments. It's brutal.
I will also add, I have a number of friends who are >= 10 years younger than I am and many of them also struggled with miscarriages in their late 20s while trying to start families.
30% of couples who don’t use birth control and who have regular sex get pregnant within one month.
60% get pregnant within three months.
80% get pregnant within six months.