Q: I had sexual intercourse with my husband late at night, and the next day my BBT showed was elevated, indicating ovulation the day before. Can I find out whether I ovulated in the morning or at night?

A: It's impossible to determine from your BBT curve whether you ovulated at night or in the morning. We can't even be 100% sure of the day. Once there is a typical rise in the temperature, all we can say is that ovulation probably happened about 24-36 hours prior to that rise.