Is a 40 day cycle considered regular or irregular? when does ovulation occur?

Every forty days?: If you have a period every forty days, this would mean you do have regular periods - just a lengthy span of time between them. Typically, you ovulate fourteen days before the start of the next period. So, this would be at about day twenty-seven. If trying to get pregnant, be sure to have sex so sperm is present beginning at about day twenty-five. This is only if you have a forty day cycle. Lgromko.

40 days: If your periods are regular, but 40 days apart, that may be normal for you. Ovulation would be on day 26.

Depends: If your 40 day cycle is the same every month then it is regular. Regular just means whether your cycles occur on a regular basis. Ovulation supposedly occurs 14 days before your period starts. So if your cycle is normally 40 days apart, then your ovulation would be at about day 25 of your cycle.