Why can’t I get pregnant!!

My husband and I have been trying for more then 1 year and no luck. In the beginning I didn’t track my days we would do it any random day and nothing then I started tracking my days with OPKs and tried BD on those high days and still no luck we decided to go get checked and results came back fine now idk what’s the problem if maybe we don’t do it as much I honestly don’t understand that whole fertile window. I also take prenatals hoping it would work but nothing.. So We tried it every other day during my cycle, then every 3 days when positive and also on my ovulation day and still no luck. Every month I feel like it can be the month to get that positive pregnancy I start to feel cramps and sure enough my dumb period starts so of course that means I’m not pregnant!! Now idk what else to do that will help me get pregnant.. I feel that I’m getting old and i have more energy now… any advice?? I feel like I’m running out of patience.. I see so many pregnant women and it gets me sad and disappointed how I want to get pregnant but no luck, I don’t understand how some couples don’t even try and they end up getting pregnant and both my husband and I want a baby but no luck.. idk what else to think.. 😔