ovulation day
unsafe day (when unprotected sex can to lead to conception)
アプリが排卵日を表示する。
The app shows the ovulation day.
医師に排卵日の計算方法を教えてもらった。
I had the doctor teach me how to calculate my ovulation day.
妊娠を希望するなら排卵日を把握すべきだ。
If you want to get pregnant, you should keep track of your ovulation day.