Auntie Ma, is the menstrual period measurement accurate?

Patient's question:

No

Doctor's answer:

If it's early pregnancy, coming on your period means you're not pregnant. If you're checking ovulation, there's no need to check during your period, as ovulation doesn't occur during that time. Early pregnancy tests are most accurate one week after your period is delayed. Ovulation tests should be checked daily around the middle of your cycle to determine your ovulation period.