Yes, a period can be 40 days late. While a typical menstrual cycle lasts around 28 days, it can vary naturally. Periods can range from late (up to 35-40 days) to absent altogether.
Factors like stress, weight changes, and medical conditions can contribute to irregular periods. It's important to note that a period that's significantly late (over 35 days) might indicate pregnancy or an underlying health issue, so it's always best to consult a doctor if you have concerns.