Stress can interfere with getting pregnant but it is a complex relationship. One aspect which makes it more complicated is that having a hard time conceiving can be a considerable stress in itself. People often say: "Just relax, and it will happen" and, though this can be insulting and extremely frustrating, there is a grain of truth to it.
That's because stress can affect the functioning of the hypothalamus. This is the gland in the brain that regulates appetite and emotions, as well as the hormones required to release the eggs in women and produce testosterone in men. If you or your partner are feeling stressed, you may feel less interested in having sex and may not have sex as often, which isn't going to help you get pregnant. If the effect of stress on your normal hormone levels is severe then it could result in you ovulating later in your cycle than usual or not at all. This is a recognised condition, which is sometimes called "stress-induced anovulation".
It's important to differentiate between constant and sudden stress. Your body often gets used to constant, everyday stresses so you'll probably ovulate fairly consistently each cycle. It's a sudden stress, such as a death in the family, which can throw your cycle off and interfere with conceiving. But this varies from woman to woman. Some women find that even a business trip away can delay ovulation, while others find that a severely traumatic incident doesn't affect their cycle at all.
It's also important to note that positive stress can affect your cycle; again, you might ovulate later or not at all. Brides often report strange cycles because they're happily stressed about their weddings. Women who go back-packing round the world may also find their periods stop temporarily. It doesn't matter that the stress is good; it can still affect ovulation.
