Is it possible... ttc help

Bekah

Been ttc for awhile now. Is it possible that I am ovulating at night while sleeping? Tried doing ovulation test all month last month with no positive. When should I test to know when I’m ovulating or not. My mc is always between 28-35 days. Never a set amount of days between each one. I feel hopeless at this point. We’ve been trying for close to 8 months now with nothing working.