A typical period lasts 2 to 7 days, with most people bleeding for about 5 days. Your cycle (the time from the first day of one period to the first day of the next) normally falls between 21 and 35 days. Bleeding that extends beyond 7 days is considered heavy and worth bringing up with a healthcare provider.
What Happens Inside Your Body
Your period is triggered by a drop in two hormones: estrogen and progesterone. In the first half of your cycle, estrogen thickens the lining of the uterus in preparation for a potential pregnancy. After ovulation, progesterone takes over, stabilizing that lining and stopping further growth. If no pregnancy occurs, progesterone levels fall sharply, and the lining sheds. That shedding is your period.
How quickly your body completes this shedding process determines how many days you bleed. The heaviest flow usually happens in the first two or three days, when the most lining is being expelled. By the final days, your body is clearing out the last traces, which is why bleeding tapers off and flow becomes lighter.
How Blood Changes Day by Day
The color and texture of your period blood shift as bleeding progresses, and all of these changes are normal. On the first day, blood often looks pink because fresh red blood mixes with the clear or milky discharge already present in the vagina. By day two, the blood is typically bright red, a sign of steady, fresh flow. A few days in, the color deepens to dark red as older blood that pooled briefly in the uterus makes its way out. You may notice thicker blood or small clots during this phase.
Toward the end, blood turns brown. This is simply older blood that has been exposed to oxygen longer, giving it a darker appearance. It often mixes with vaginal discharge, creating a dark brown spotting that can linger for a day or two before the period fully ends.
Teens and Early Periods
If you or your child recently started menstruating, expect some unpredictability. It can take a few years after menarche (the first period) for the hormonal feedback loop to mature, so cycles may be longer, shorter, or spaced unevenly. A period that lasts 3 days one month and 6 the next is not unusual during this window.
That said, bleeding that consistently runs longer than a week, even in the first couple of years, is a reason to check in with a pediatrician. So is soaking through a pad or tampon every hour, or periods that arrive more frequently than every 21 days.
How Perimenopause Changes Things
As you approach menopause, your cycles shift again. Perimenopause typically begins in your 40s, and the most dramatic changes happen in the final years before periods stop entirely. A 2006 study tracking women through perimenopause found that average cycle length climbed from about 30 days four years before menopause to over 80 days in the final year. In that last year, the majority of women spent at least 75% of their time in cycles longer than 40 days.
The bleeding itself can also change. Some perimenopausal periods are heavier and longer than what you experienced in your 30s, while others are surprisingly short. This variability is driven by fluctuating hormone levels as the ovaries gradually wind down production.
Periods After Pregnancy
If you’re breastfeeding, your period may not return for months or even longer after delivery. The hormones that support milk production suppress ovulation, and how quickly your cycle resumes depends on your baby’s feeding patterns. Periods are more likely to return once your baby starts breastfeeding less frequently, sleeping through the night, or eating solid foods. If you’re not breastfeeding, periods typically resume within a few months postpartum.
Either way, the first several cycles back are often irregular. You might skip a month, or find that your period is heavier or lighter than it was before pregnancy. This usually settles as your hormonal rhythm re-establishes itself.
How Birth Control Affects Duration
Hormonal birth control is one of the biggest modifiers of period length and flow. Combination pills (which contain both estrogen and a synthetic progesterone) generally make periods lighter and shorter. If you skip the placebo week and move directly to the next pack, you can skip the withdrawal bleed entirely.
Hormonal IUDs work differently but often produce a similar result. Some studies estimate that after one year with a hormonal IUD, there’s about a 20% chance of going 90 days or more without a period. On the flip side, heavier or longer bleeding is possible in the first few months after IUD insertion as your body adjusts. Copper IUDs, which don’t contain hormones, tend to make periods heavier and longer, especially in the first year.
When Bleeding Lasts Too Long
The CDC defines heavy menstrual bleeding as periods lasting more than 7 days or flow heavy enough that you need to change your pad or tampon nearly every hour. Women with heavy periods lose roughly twice as much blood per cycle as average. If you’re regularly bleeding past the 7-day mark, several conditions could be involved.
Polycystic ovary syndrome (PCOS) disrupts the normal hormonal cycle, often causing infrequent periods. People with PCOS commonly have fewer than 8 periods a year. When a period does arrive after a long gap, the uterine lining has had more time to build up, which can make the bleed heavier and longer than usual. Endometriosis, fibroids, thyroid disorders, and clotting conditions can also extend bleeding duration.
Soaking through a pad or tampon every hour is a signal to seek medical attention promptly, especially if accompanied by dizziness, fatigue, or shortness of breath, which can indicate significant blood loss.
Tracking What’s Normal for You
Population averages are useful benchmarks, but your own pattern matters more. Someone who consistently bleeds for 3 days has a different normal than someone who reliably goes 6. The key question isn’t whether your period matches a textbook number. It’s whether something has changed from your usual pattern, and whether that change persists.
Tracking your cycle for a few months gives you a personal baseline. Note the start and end dates, flow intensity, and any symptoms. If your periods suddenly become significantly longer, heavier, or more painful than your established pattern, that shift is worth investigating regardless of whether you fall inside or outside the 2 to 7 day range.