Why why why

Just need to rant a bit. I just don’t understand why I was able to get pregnant with my first two so easily...both the first month of trying. It’s been 6 months since we started trying for number 3...why is it so difficult this time?! I had high hopes for this cycle but nope af showed her ugly f-ing face today. He wants to keep trying, idk if I can handle the emotional toll it’s taking on me and I battle severe depression and anxiety already as it is and this isn’t helping any. He wants to go get checked to see if he’s the reason but I’ve said no since we already have two we should be grateful for them and stop trying for the 3rd. Idk I’m just so distraught. 😢😢