Okay, here is an article titled "When is ovulation on menstrual period No. 7?":

For many women, having your period on the 7th is as important as trying to get pregnant. So, when is the ovulation date on menstrual period No. 7? This question is especially important for women who want to have children, because ovulation is the best time to get pregnant.

Generally, a woman's menstrual cycle is 28 days long, but some may have fluctuating days. Therefore, if you have your period on the 7th, ovulation usually occurs 14 days before your next period. In other words, if you have your period on the 7th, ovulation usually occurs around the 10th.

However, this is only a rough guide. Everyone's situation is different, so if you're trying to get pregnant, it's best to talk to your doctor or professional counselor to make sure you're having sex at the right time and getting pregnant.