What am I doing wrong

I just dont understand what I'm doing wrong... this app pin points AF to the exact day every single month, and my cycles are pretty much the exact same each month. My boy and I have been now trying for almost a year and still nothing but red. I was on the depo for 8 years prior to stopping 2 years ago but I've heard horror stories of it messing with fertility and now I'm worried that may be true. Were doing attempts every other day starting the day Af goes away until my next one begins... hes had an ex get pregnant before over 10 years ago so his swimmers should in theory still be working.... and ive had a child 11 years ago.. so its confusing disappointing and such depression filling I'm ready to give up because I cant take the letdowns anymore.