28 day cycle. Normally I get mild pelvic pain on the midnight of cd13. Best time to intercourses to achieve pregnancy if I ovu on 13th midnight?

Day 12. With a 28-day cycle, ovulation happens around day 14. That is day 14 counting from the beginning of a period (the first day of bleeding is day 1). That is also known as 14 days after LMP, which means last menstrual period. If wanting a baby, start having sex twice a day on Day 11, for 6 days... and enjoy those days, WITHOUT thinking about pregnancy, babies, or anything related to cycles.