Hi, I understand how you feel. Just to share... Husband & I tried very hard after 2 miscarriages. Only later, I realised I didn't get my ovulation date right. Try to monitor your cervical mucus. Women usually ovulate when your cervical mucus are white & wet. For a 28days cycle, I should ovulate on day 14-15, however my last ovulation happen on day 12-13 when I noticed my cervical mucus as 'wet & slippery'. I tested using clearblue OPK & I saw a smiley face & my pregnancy was successful. Don't trust app dates, its not accurate as it doesn't understand our body. Good luck! Don't give up hope!
Don't give up! Do consult a fertility specialist if you can, take care!