It's completely understandable to feel stressed when there's a change in your cycle, especially if it's normally consistent. There are a variety of reasons why you might experience a delay in your period other than pregnancy. Stress is actually one of the most common factors; significant stress can affect the hypothalamus, which is the part of your brain responsible for regulating your cycle.
Changes in weight, whether gain or loss, can also impact your menstrual cycle due to shifts in body fat, which affects estrogen levels. Similarly, intense exercise can sometimes lead to missed periods, especially if it's a new activity or particularly rigorous routine.
Another possibility is a hormonal imbalance, such as with thyroid issues or polycystic ovary syndrome (PCOS), both of which are known to affect menstrual regularity. Certain medications, particularly those affecting hormonal levels, may also cause changes.
If you're on birth control or have recently stopped taking it, that might also be a reason for delay or irregularity. Lastly, perimenopause, which can start several years before menopause, might lead to irregular cycles in some women in their late 30s or 40s.
If the missed period continues or you have other symptoms, it might be a good idea to check in with a healthcare professional. They can offer more precise insights and might recommend tests if they suspect an underlying issue. Have you had any significant life changes recently that could have affected your routine or stress levels?