Getting pregnant again after a miscarriage.

Is it true that once you have gotten pregnant, it's easier to get pregnant again? I had a miscarriage recently and am just curious. I thought I would ask here before I do further research. I have two relatives that had a really hard time becoming pregnant but after their first child was born, they conceived again very quickly. Maybe there is no validity to this, but would be interested in any information you all have! Thanks!