islaLast period started in September: when is the next one?
Find the day your last period started in the left column and your usual cycle length along the top. The date where they meet is the estimated start of your next period. September has 30 days.
With a 21-day cycle, a period that starts on September 1 to 9 is followed by the next one before September ends. With a 28-day cycle, a period that starts on September 1 to 2 is followed by the next one before September ends.
| Last start | 21-day cycle | 25-day cycle | 28-day cycle | 30-day cycle | 32-day cycle | 35-day cycle |
|---|---|---|---|---|---|---|
| Sep 1 | Sep 22 | Sep 26 | Sep 29 | Oct 1 | Oct 3 | Oct 6 |
| Sep 2 | Sep 23 | Sep 27 | Sep 30 | Oct 2 | Oct 4 | Oct 7 |
| Sep 3 | Sep 24 | Sep 28 | Oct 1 | Oct 3 | Oct 5 | Oct 8 |
| Sep 4 | Sep 25 | Sep 29 | Oct 2 | Oct 4 | Oct 6 | Oct 9 |
| Sep 5 | Sep 26 | Sep 30 | Oct 3 | Oct 5 | Oct 7 | Oct 10 |
| Sep 6 | Sep 27 | Oct 1 | Oct 4 | Oct 6 | Oct 8 | Oct 11 |
| Sep 7 | Sep 28 | Oct 2 | Oct 5 | Oct 7 | Oct 9 | Oct 12 |
| Sep 8 | Sep 29 | Oct 3 | Oct 6 | Oct 8 | Oct 10 | Oct 13 |
| Sep 9 | Sep 30 | Oct 4 | Oct 7 | Oct 9 | Oct 11 | Oct 14 |
| Sep 10 | Oct 1 | Oct 5 | Oct 8 | Oct 10 | Oct 12 | Oct 15 |
| Sep 11 | Oct 2 | Oct 6 | Oct 9 | Oct 11 | Oct 13 | Oct 16 |
| Sep 12 | Oct 3 | Oct 7 | Oct 10 | Oct 12 | Oct 14 | Oct 17 |
| Sep 13 | Oct 4 | Oct 8 | Oct 11 | Oct 13 | Oct 15 | Oct 18 |
| Sep 14 | Oct 5 | Oct 9 | Oct 12 | Oct 14 | Oct 16 | Oct 19 |
| Sep 15 | Oct 6 | Oct 10 | Oct 13 | Oct 15 | Oct 17 | Oct 20 |
| Sep 16 | Oct 7 | Oct 11 | Oct 14 | Oct 16 | Oct 18 | Oct 21 |
| Sep 17 | Oct 8 | Oct 12 | Oct 15 | Oct 17 | Oct 19 | Oct 22 |
| Sep 18 | Oct 9 | Oct 13 | Oct 16 | Oct 18 | Oct 20 | Oct 23 |
| Sep 19 | Oct 10 | Oct 14 | Oct 17 | Oct 19 | Oct 21 | Oct 24 |
| Sep 20 | Oct 11 | Oct 15 | Oct 18 | Oct 20 | Oct 22 | Oct 25 |
| Sep 21 | Oct 12 | Oct 16 | Oct 19 | Oct 21 | Oct 23 | Oct 26 |
| Sep 22 | Oct 13 | Oct 17 | Oct 20 | Oct 22 | Oct 24 | Oct 27 |
| Sep 23 | Oct 14 | Oct 18 | Oct 21 | Oct 23 | Oct 25 | Oct 28 |
| Sep 24 | Oct 15 | Oct 19 | Oct 22 | Oct 24 | Oct 26 | Oct 29 |
| Sep 25 | Oct 16 | Oct 20 | Oct 23 | Oct 25 | Oct 27 | Oct 30 |
| Sep 26 | Oct 17 | Oct 21 | Oct 24 | Oct 26 | Oct 28 | Oct 31 |
| Sep 27 | Oct 18 | Oct 22 | Oct 25 | Oct 27 | Oct 29 | Nov 1 |
| Sep 28 | Oct 19 | Oct 23 | Oct 26 | Oct 28 | Oct 30 | Nov 2 |
| Sep 29 | Oct 20 | Oct 24 | Oct 27 | Oct 29 | Oct 31 | Nov 3 |
| Sep 30 | Oct 21 | Oct 25 | Oct 28 | Oct 30 | Nov 1 | Nov 4 |
Periods often start a few days either side of an estimate. Every date here is an estimate from a typical cycle length. It is not birth control and it is not medical advice.
Log the first day of each period in Isla and it keeps the next estimate, a range and the calendar up to date on your iPhone. No account and no ads.
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