How many DPO am I today?
Type the day you ovulated, or the first day of your last period and your cycle length. The DPO calculator counts the days past ovulation (DPO) on any day and shows where you are in the two-week wait. It is an estimate, not medical advice.
- Days past ovulation
- 7
On October 5, 2026 you are 7 days past ovulation (DPO).
- What usually happens
- In the implantation window (6 to 12 DPO)
- Ovulation
- September 28, 2026
- Next period due
- October 12, 2026
- Days until the period is due
- 7
- Implantation window from
- October 4, 2026
- Implantation window to
- October 10, 2026
Answer for the example date Monday, October 5, 2026. It changes to today's date when the page loads.
Days past ovulation: 7. On October 5, 2026 you are 7 days past ovulation (DPO).
Where am I in the two-week wait?
This calculator gives general information only. It is not medical advice and does not replace a doctor or other health care provider. Talk with a professional about your results. Terms of use
How to calculate
Counts the days past ovulation (DPO) on a chosen day, from the ovulation day or the last period and cycle length, and says what usually happens at that DPO: implantation, the period due date, and when a test is reliable.
Example with the default inputs (What do you know? Last period, First day of your last period September 14, 2026, Cycle length (days) 28, DPO on October 5, 2026) on the example date Monday, October 5, 2026: On October 5, 2026 you are 7 days past ovulation (DPO).
Method: DPO = chosen day − ovulation day; ovulation = last period + cycle length − 14 days (or the day entered); period due = ovulation + 14 days.
- Ovulation comes 14 days before the next period (ACOG average); real cycles vary.
- Implantation happened 6 to 12 days after ovulation, most often on day 8, 9 or 10 (Wilcox and others, 1999).
- Most home pregnancy tests are reliable from the first day of a missed period (womenshealth.gov).
Worked examples
Each example is checked against the calculator on every build.
- What do you know? Last period, First day of your last period 2026-09-01, Cycle length (days) 28, DPO on 2026-09-24 gives Ovulation 2026-09-15, Days past ovulation 9, What usually happens In the most likely implantation days (8 to 10 DPO), Next period due 2026-09-29, Days until the period is due 5, Implantation window from 2026-09-21, Implantation window to 2026-09-27.Source: ACOG Committee Opinion 700, Methods for Estimating the Due Date (ovulation about 14 days before the next period), https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/05/methods-for-estimating-the-due-date; Wilcox AJ, Baird DD, Weinberg CR, Time of implantation of the conceptus and loss of pregnancy, N Engl J Med 1999;340:1796 (implantation 6 to 12 days after ovulation, 84% on day 8, 9 or 10), https://doi.org/10.1056/NEJM199906103402304
- What do you know? Ovulation day, Ovulation day 2026-12-25, DPO on 2027-01-08 gives Days past ovulation 14, Next period due 2027-01-08, Days until the period is due 0, What usually happens Period due today: a home pregnancy test is reliable from a missed period.Source: ACOG Committee Opinion 700, Methods for Estimating the Due Date (ovulation about 14 days before the next period), https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/05/methods-for-estimating-the-due-date
- What do you know? Last period, First day of your last period 2028-02-10, Cycle length (days) 32, DPO on 2028-03-03 gives Ovulation 2028-02-28, Days past ovulation 4, Next period due 2028-03-13.Source: ACOG Committee Opinion 700, Methods for Estimating the Due Date (ovulation about 14 days before the next period), https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/05/methods-for-estimating-the-due-date
How it works
- Ovulation day. Entered, or estimated as the first day of the last period + cycle length − 14 days (a 28-day cycle gives day 14 after the period started).
- Days past ovulation (DPO) = the chosen day − the ovulation day, in calendar days. The ovulation day itself is 0 DPO.
- Next period due = ovulation + 14 days. Days until the period is due = 14 − DPO (0 on the due day, negative when late).
- Implantation window = ovulation + 6 days to ovulation + 12 days (Wilcox and others, 1999).
- What usually happens, by DPO: 0 “Ovulation day”; 1 to 5 “Before implantation”; 6, 7, 11 and 12 “In the implantation window (6 to 12 DPO)”; 8 to 10 “In the most likely implantation days (8 to 10 DPO)”; 13 “After the implantation window, before the period is due”; 14 “Period due today”; 15 or more “Period late”.
Rules. The cycle length is 20 to 45 days. A day before the ovulation day has no DPO, and a day more than 60 days past ovulation gives no answer. Dates follow the calendar, leap days included.
Assumptions
- A luteal phase of 14 days; real cycles vary by a few days.
- An estimate for planning, not a sign of pregnancy.
Worked examples by hand
Last period September 1, 2026, 28-day cycle, counted on September 24. Ovulation = September 1 + (28 − 14) = September 15. DPO = September 24 − September 15 = 9: in the most likely implantation days. Period due September 15 + 14 = September 29, 5 days away. Implantation window September 21 to 27.
Ovulation December 25, 2026, counted on January 8, 2027. December 25 to January 8 is 6 + 8 = 14 days, so 14 DPO. The period is due January 8 (0 days away).
Last period February 10, 2028, 32-day cycle, counted on March 3. Ovulation = February 10 + 18 = February 28. 2028 is a leap year, so February 28 to March 3 is 4 days: 4 DPO, before implantation. Period due March 13.
Other questions people ask
What does DPO mean?
DPO stands for days past ovulation. The ovulation day is 0 DPO, the next day 1 DPO, and so on. People trying to conceive use it to time a pregnancy test during the two-week wait before the next period.
How do I work out my DPO?
Count the days from your ovulation day to today. If you do not know the ovulation day, estimate it as the first day of your last period plus your cycle length minus 14 days. With a 28-day cycle that started on September 1, ovulation is about September 15, so September 24 is 9 DPO.
When does implantation happen?
In a 1999 study that tracked hormones daily, implantation happened 6 to 12 days after ovulation, and on day 8, 9 or 10 in 84% of the pregnancies. So 6 to 12 DPO is the usual window.
How many DPO can I take a pregnancy test?
The hCG hormone appears only after implantation and then rises. Most home tests are reliable from the day of a missed period, which is about 14 DPO in a regular cycle. Testing earlier can give a negative result even when you are pregnant.
Is my period late at 15 DPO?
If ovulation was on the day you think, the period is due about 14 days after it, so at 15 DPO it is a day late. Ovulation dates are often off by a few days, especially when they are estimated from the last period.
Why is the luteal phase 14 days?
The time from ovulation to the next period is the luteal phase. It is about 14 days on average and varies less than the first part of the cycle, which is why the cycle length minus 14 gives the ovulation day.