Periods may be annoying, but at least they're predictable - sort of. If yours is a little delayed this cycle, and you're not trying to get pregnant right now, your first instinct is probably to freak out a bit. But don't.

大姨妈很讨人厌，但至少是可以预测的--一般而言。如果这次经期延后了，而你又没在备孕，那你可能会本能地吓一跳。但千万别担心。

There are actually many things that can delay your period that have nothing to do with being pregnant. For instance, many medications list delayed periods as a side effect, especially psychiatric drugs that can elevate your levels of prolactin. (This hormone¹ is produced in low levels by your body at all times, but it becomes elevated during and right after pregnancy² to help you produce breast milk.) "Usually women get told [about the possibility] because it's a relatively³ common side effect" of these medications, explains Raquel B. Dardik, MD at the NYU Langone Medical Center. "So it's not usually much of a surprise."

很多事情都会导致经期延迟，而且这些因素与怀孕一点关系都没有。例如，许多药物都会注明有延迟经期的副作用，尤其是提高催乳素水平的精神药物。（人体总是分泌少量的催乳素，但孕期和孕后，催乳素分泌量会有所提高，有助于奶水分泌。）"通常，女性会被告知经期延后的可能性，因为这是这些药物带来的相对普遍的副作用"，纽约大学兰格恩医学中心的拉克尔·B·达迪克医学博士解释道。"所以经期延迟算不上惊喜。"

Click through to see other possible reasons why your period might be tardy⁴ this month.

继续点下去，看看导致经期延后的可能原因还有哪些。

1. Stress

1. 压力

One of the most common causes of a later period is, unfortunately, stress. That's because when you're stressed, your level of the hormone cortisol increases. And, says Dr. Dardik, "that can delay ovulation or suppress it altogether."

不幸的是，导致经期延后最常见的原因之一就是压力。因为当你感到压力时，你的激素皮质醇水平就会升高。而且，达迪克博士说"那会延迟身体排卵，或是完全抑制排卵。"

Of course, "that's sort of a double whammy," Dr. Dardik says, because you're already stressed and being worried about a missed period isn't exactly going to help that situation. So if you've been through some trying times or experienced heightened anxiety recently, give yourself a break and be patient.

当然，"那是种双重打击，" 达迪克博士说，因为你本来就已经备受压力了，而担心大姨妈延迟根本不会解决这个问题。所以，如果你最近经历了困难时期或高度焦虑，那为何不放松一下，耐心等待呢？

2. Extreme Circumstances

2. 极端情况

Stress certainly counts in this category. But if you've been through other extreme situations recently, your period may be out of whack⁵.

当然，压力也属于这一范畴。但如果你最近经历了其它极端情况，那经期失常也就不足为奇了。

That could include life changes like major surgery or significant weight loss associated with an eating disorder⁶, Dr. Dardik says. It could also include a traumatic experience, such as sexual assault, a loss of a loved one, or a really bad car accident. So if you've been through a major life moment, consider that your late period could be a symptom of that. Check in with your doctor to pin it down and if you're really having trouble, don't be shy about seeking the help of a mental health counselor⁷.

极端情况包括生活发生了变化，比如重大的外科手术或伴随饮食紊乱而来的体重骤减，达迪克博士说道。可能还包括一次巨大的创伤，比如：性侵、失去心爱的人、或严重的车祸。所以，如果现在是你人生发生重大变化的时刻，那经期延后可能也是症状之一。如果真的有问题，请咨询自己的医生，采取相应措施，不要害怕寻求心理健康咨询师的帮助。