Unfairness

How do the most unprepared woman pop out babies like it’s nothing? I know so many woman and teenagers have babies and have other people/family take care of them. Me and my Fiancé have only been trying to a little over a month, we had our first negative and it broke me. I feel terrible feeling bad because there are people who have been trying for years and still aren’t pregnant. I’ve recently gotten of Nexplanon because of incredibly bad cramping. We thought it was an ectopic pregnancy but tests came back negative. We were both very bummed about it. Now I’m constantly in fear that because my birth control was in wrong it messed up having chances of getting pregnant. I try not to stress about what part of my cycle I’m in but I’m 3 DPO and I’m so scared it’s another negative.