This question is usually answered in terms of calendar months.
People think "ok, I decided to get pregnant last april so... a year!"
Wrong.
That's the time that has passed since you set the intention to get pregnant, but it's no t the same as actively trying to become pregnant.
To get pregnant you need a lot of things to be in order! Do you know how many of those Cycles you actually had sex in your fertile window? Do you know the quality of your partner's sperm? Do you know if your progesterone was high enough to support a pregnancy?
All of those things make a difference between an intention month, or a targeted month.