13dpo today but BFN at 12dpo

I am very frustrated today. I posted here 2 years ago when i got pregnant with my first child which took us 2 1/2 years before I finally conceived. We started trying for our second since January and so far until now still not happening. I am very frustrated because we do everything we can from tracking my ovulation day and BD during fertile days, using preseed and according to OPK (ovulation predictor kit) i am ovulating every month, but why can't I get pregnant? I am so scared that it might not happen anymore when my first child took neary 2 years for us to conceived. I tested yesterday at 12dpo but it's BFN, period due in two days. SOmetimes I feel like crying but no tears anymore, I want to relax but it's hard when you have this fear that it might not happen anymore and you badly waNT it.. Well, just trying to breathe really..thanks for reading..