What if I do not know my usual cycle length?

Write the dates you know. Use the range method once you have more start dates.

Can this worksheet tell me why my period is late?

No. It only helps with date math and planning.

Yes, as a simple calendar sheet. ACOG says cycles can take years to become regular after a first period.

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Next Period Date Estimate Worksheet

A plain worksheet for estimating your next period date from recent period starts, with a range for planning and no claim that the date is exact.

Your next period date is a guess.

A good guess can still help.

It can tell you when to pack supplies.

It can help you plan travel, work, school, or sleep.

Start with the last date

Use the first day your period started.

Field Your note Last period start date Date before that Date before that Date before that

If you have only one date, save it.

You can make a better estimate after the next start date.

Choose your date math

If you know Do this Result Last cycle length Add it to your last start date One estimate Three or more cycle lengths Add the average to your last start date One middle estimate Shortest and longest cycle Add both to your last start date A planning range

The range is the most useful plan.

It leaves room for normal date changes.

Estimate table

Step Your work Last period started Shortest recent cycle length Longest recent cycle length Add shortest length to last start date Add longest length to last start date My next period may start between

Do not use this range as a health answer.

Do not use it to decide what a late date means.

Use it to plan.

One week prep list

Fill this out before your estimate range starts.

Item Done Note Products in bag Products near bed Work or school backup Pain or comfort items, if you use them Laundry done Travel kit packed Private notes reviewed

Keep the list small.

You do not need to log every detail.

If the date changes

Write the real start date.

Then update your next estimate.

What changed Your note Estimated range Real start date Days earlier or later than estimate Any context I want to remember Anything I do not want to keep

For timing notes, use the early or late period timing log.

For a broader note page, use the late period context log.

What sources say

Office on Women's Health says a period may be regular but still only predictable within a few days.

It also says cycles can vary from month to month.

MedlinePlus says most cycles last about 28 days, but cycles can be shorter or longer.

ACOG says young people may have wider cycle ranges after periods begin.

That is why this sheet uses a range.

Link this to your calendar

Write only what you need.

Calendar note Private note "Pack period kit" Period estimate range "Laundry" Product refill count "Travel supplies" Expected period range "Move white pants" Optional clothing note