Started opk this month. Based on my last two periods my menstrual cycle is 30 days, so I started CD…

Started opk this month. Based on my last two periods my menstrual cycle is 30 days, so I started CD 13. Luteal phase set at 14 days I’m due to ovulate tomorrow according to my app. However, the line looks pretty solid today, CD 15. Does it look like a LH surge, or do you think tomorrow will be stronger?