Ovulation help!!!!!!!!!!!

🎀Erica 🎀 • Baby #2 is on the way thank you God!! 🙏🏾🙌🏾 I pray a healthy 6 more months for the both of us!! EDD: Oct 12, 2016👶🏽
All my apps are telling me the 18th cycle day 19 is when ill ovulate I've been testing but still negative opks is this normal when I'm only 4 days alway??? Any advice is welcomed..