The older you are, the longer it could take you to get pregnant. Again, not always the case, not for a longshot, but medically speaking, your egg quality does begin to decline as you get older. Because you were born with all the eggs you’ll ever have, as you age, fewer of them are around to meet up with the sperm when the time comes. That being said, there are women in their 20’s who have trouble conceiving and women in their 40’s who don’t. It’s totally case by case, so don’t stress it preemptively.