Discouraged 😔

I’m really discouraged right now. I just found out my sister in law is pregnant, unplanned, again. My husband has three sisters, each have had/are pregnant with two unplanned babies EACH. Meanwhile, my husband and I have been together for 10 years (married for 3), and trying for 3 years and still nothing. Nothing. How does this happen? I’ve had a niece or nephew born every year since 2014, and I love each of them dearly. I just don’t get how three people can “accidentally” get pregnant twice, and I can’t even do it once while trying my damnedest. 😔