When do I ovulate?! Please help!


At started on July 25 and last 5 days. Glow and Ovia predicted ovulation to be on the 7th. I took an opk yesterday and it was positive, the line was super dark. Once I logged the opk on my calendar it moved my ovulation to today. It shows I’ve only been fertile maybe 5 days. Is this accurate? I took another opk this morning but the line was lighter.