I'd add that three days is really just a guideline, but everyone's body is different. For me, for example, my normal rhythm was once every two days, and when it stretched to a week with belly pain and bloating, I realized something was off. Turned out it was my diet and not drinking enough water. Now I keep an eye on it and adjust what I eat as soon as I notice any discomfort.
The main thing is not just to count the days, but to listen to your body: if you're feeling pain, bloating, general malaise, or you notice blood, that's a sign to see a doctor, even if it's only been a couple of days 😊