How do people plan a pregnancy and get pregnant,

when I hear a lot of people say it happens when you " least expect it " or by accident.

So

How the hell do you plan to get pregnant and get pregnant cause I'm been trying for a long time and nothing. I believe I can't get pregnant or anything.

Last time I was pregnant I was on birth control on the depo and it didn't work. We both didn't expect it. But it ended in a miscarriage anyways. 2014. Now I'm here still trying and I'm not pregnant