Your period has been your companion for decades—sometimes unwelcome, often inconvenient, but predictable. Now it’s doing something new.
Menstrual changes are often the first sign that perimenopause has begun, sometimes years before you notice anything else. And they can be deeply disorienting: cycles that were like clockwork suddenly aren’t.
Early Changes
In early perimenopause, many women notice:
Shorter cycles. Your period might come every 24 days instead of 28. This happens because the follicular phase (the time before ovulation) shortens as your ovaries become less responsive. More frequent periods can feel like more bleeding overall—because it is.
Heavier flow in some cycles. When estrogen runs high without adequate progesterone to balance it (because you didn’t ovulate that month, or ovulated weakly), your uterine lining builds up more. When it finally sheds, it sheds heavily.
LOOP cycles. “Luteal Out-Of-Phase events”—a technical term for cycles where things don’t follow the expected pattern. Your body is trying, but the usual coordination is faltering.
Later Changes
As perimenopause progresses:
Longer gaps appear. Sixty days or more between periods. You might wonder each time: is this it? And then it comes back.
When periods do come, they may be heavier. With less regular ovulation comes less progesterone, and without progesterone to regulate the endometrium, bleeding can be substantial.
Timing becomes unpredictable. You can’t plan around it anymore. It arrives when it arrives.
More anovulatory cycles. Months where you don’t ovulate at all become more common. No ovulation means no progesterone production for that cycle—which affects mood, sleep, and bleeding patterns.
Where Are You in This?
Researchers have mapped out the stages (called STRAW+10):
Early perimenopause: Cycle length starts varying by 7 or more days from your usual pattern. Things are shifting, but periods still come.
Late perimenopause: You start skipping cycles—60 or more days without a period. This stage typically lasts 1-3 years before your final period.
Postmenopause: It’s been 12 months since your last period. You’re through.
When to Seek Evaluation
Irregular periods are normal during this transition. But certain patterns warrant a conversation with your provider:
- Very heavy bleeding—soaking through a pad or tampon every hour for several hours
- Bleeding that lasts more than 7 days
- Bleeding after sex
- Any bleeding after 12 months without a period (this is postmenopausal bleeding and always needs evaluation)
- Bleeding patterns that concern you for any reason
Don’t dismiss your own instincts. If something feels wrong, it’s worth asking about.
The Emotional Weight
There’s something about menstrual changes that can feel unexpectedly significant. This cycle has been part of your life since adolescence. Watching it become erratic—or preparing for it to end entirely—can bring up feelings you didn’t anticipate.
Grief. Relief. Both at once.
Whatever you’re feeling is allowed. This is an ending and a beginning, and both of those carry weight.
You may also find it helpful to understand what’s driving these changes. See The Hormonal Landscape for the full picture of what your body is doing.