Needing super tampons on a heavy day is one thing—but regularly changing your tampon every hour on the hour is another, says Mary Jane Minkin, M.D., a board-certified ob-gyn and a clinical professor at Yale University School of Medicine. If you’re swapping out feminine products every 60 minutes for more than a day, check in with your ob-gyn, she says. The concern isn’t necessarily uterine abnormalities (although fibroids and polyps could certainly be at play). The bigger issue is the blood loss, says Minkin. It’s an issue you’ll want to take seriously, as too much can result in fatigue, dizziness, and even fainting. To get to the bottom of things, your doc might do a complete blood count (CBC) test to see if you need more iron in your diet, for example, says Minkin.