Name Date
Implantation Date worksheet
Grades 3–4
Calcapedia Solve each problem and show your work. Round answers to 2 decimal places where needed.
- 1.
Problem 1. - I know: The first day of my last period
- First day of last period: Nov 22, 2024
- Average cycle length: 38 days
Find: Most likely implantation days
Answer
- 2.
Problem 2. - I know: The first day of my last period
- First day of last period: Jun 20, 2026
- Average cycle length: 32 days
Find: Most likely implantation days
Answer
- 3.
Problem 3. - I know: My ovulation date
- Ovulation date: Oct 23, 2025
Find: Most likely implantation days
Answer
- 4.
Problem 4. - I know: My ovulation date
- Ovulation date: Apr 7, 2025
Find: Most likely implantation days
Answer
- 5.
Problem 5. - I know: My ovulation date
- Ovulation date: Jan 27, 2025
Find: Most likely implantation days
Answer
- 6.
Problem 6. - I know: My ovulation date
- Ovulation date: Aug 10, 2026
Find: Most likely implantation days
Answer
- 7.
Problem 7. - I know: My ovulation date
- Ovulation date: May 6, 2025
Find: Most likely implantation days
Answer
- 8.
Problem 8. - I know: My ovulation date
- Ovulation date: Nov 11, 2025
Find: Most likely implantation days
Answer
- 9.
Problem 9. - I know: The first day of my last period
- First day of last period: Aug 21, 2026
- Average cycle length: 24 days
Find: Most likely implantation days
Answer
- 10.
Problem 10. - I know: The first day of my last period
- First day of last period: Apr 23, 2025
- Average cycle length: 32 days
Find: Most likely implantation days
Answer
Answer key: Implantation Date worksheet
Calcapedia 1. Most likely implantation days: Dec 24, 2024 – Dec 26, 2024
Ovulation is estimated 14 days before the next period, so subtract 14 from the cycle length
Add that to the first day of the last period to estimate ovulation
In the research this uses, implantation most often happened 8 to 10 days after ovulation, so add those days
It was seen as early as 6 and as late as 12 days after ovulation, which gives the wider window
Your next period is due about 14 days after ovulation. That is the usual day to take a home test
2. Most likely implantation days: Jul 16, 2026 – Jul 18, 2026
Ovulation is estimated 14 days before the next period, so subtract 14 from the cycle length
Add that to the first day of the last period to estimate ovulation
In the research this uses, implantation most often happened 8 to 10 days after ovulation, so add those days
It was seen as early as 6 and as late as 12 days after ovulation, which gives the wider window
Your next period is due about 14 days after ovulation. That is the usual day to take a home test
3. Most likely implantation days: Oct 31, 2025 – Nov 2, 2025
In the research this uses, implantation most often happened 8 to 10 days after ovulation, so add those days
It was seen as early as 6 and as late as 12 days after ovulation, which gives the wider window
Your next period is due about 14 days after ovulation. That is the usual day to take a home test
4. Most likely implantation days: Apr 15, 2025 – Apr 17, 2025
In the research this uses, implantation most often happened 8 to 10 days after ovulation, so add those days
It was seen as early as 6 and as late as 12 days after ovulation, which gives the wider window
Your next period is due about 14 days after ovulation. That is the usual day to take a home test
5. Most likely implantation days: Feb 4, 2025 – Feb 6, 2025
In the research this uses, implantation most often happened 8 to 10 days after ovulation, so add those days
It was seen as early as 6 and as late as 12 days after ovulation, which gives the wider window
Your next period is due about 14 days after ovulation. That is the usual day to take a home test
6. Most likely implantation days: Aug 18, 2026 – Aug 20, 2026
In the research this uses, implantation most often happened 8 to 10 days after ovulation, so add those days
It was seen as early as 6 and as late as 12 days after ovulation, which gives the wider window
Your next period is due about 14 days after ovulation. That is the usual day to take a home test
7. Most likely implantation days: May 14, 2025 – May 16, 2025
In the research this uses, implantation most often happened 8 to 10 days after ovulation, so add those days
It was seen as early as 6 and as late as 12 days after ovulation, which gives the wider window
Your next period is due about 14 days after ovulation. That is the usual day to take a home test
8. Most likely implantation days: Nov 19, 2025 – Nov 21, 2025
In the research this uses, implantation most often happened 8 to 10 days after ovulation, so add those days
It was seen as early as 6 and as late as 12 days after ovulation, which gives the wider window
Your next period is due about 14 days after ovulation. That is the usual day to take a home test
9. Most likely implantation days: Sep 8, 2026 – Sep 10, 2026
Ovulation is estimated 14 days before the next period, so subtract 14 from the cycle length
Add that to the first day of the last period to estimate ovulation
In the research this uses, implantation most often happened 8 to 10 days after ovulation, so add those days
It was seen as early as 6 and as late as 12 days after ovulation, which gives the wider window
Your next period is due about 14 days after ovulation. That is the usual day to take a home test
10. Most likely implantation days: May 19, 2025 – May 21, 2025
Ovulation is estimated 14 days before the next period, so subtract 14 from the cycle length
Add that to the first day of the last period to estimate ovulation
In the research this uses, implantation most often happened 8 to 10 days after ovulation, so add those days
It was seen as early as 6 and as late as 12 days after ovulation, which gives the wider window
Your next period is due about 14 days after ovulation. That is the usual day to take a home test