When Did I Conceive?

Trying to Pinpoint When You Conceived? If you’re pregnant, you might be wondering when conception happened—or even trying to determine who the father is. While it’s impossible to know the exact moment of conception, there are medically informed ways to estimate it with reasonable accuracy. Need answers quickly? Chat anonymously with a nurse for free at (928) 832-4230.
What Date Did I Conceive?
Whether you’re in the early weeks or further along in your pregnancy, estimating your conception date can be done with some basic information.
Ovulation—the time when pregnancy is most likely to occur—typically happens about 14 days after the start of your last menstrual period. This fertile window usually lasts 2 to 3 days per cycle, though timing can vary from woman to woman.
Conception Date Calculator
By counting the days from the first day of your last period, you can estimate when ovulation occurred—and with it, a likely range for conception.
If doing this calculation feels overwhelming, you can use a free online conception calculator, or text us at (928) 832-4230, and we’ll walk you through it.
Keep in mind, this is only an estimate. Everyone’s cycle is different. Some women ovulate earlier or later, and the fertile window may last longer in some cases.
Can Conception Happen Outside the Ovulation Window?
Yes. Even if sex happened before ovulation, pregnancy is still possible. That’s because sperm can live inside the female reproductive tract for up to five days, allowing time for fertilization once an egg is released.¹ ²
Conception Calculator
Conception Date from Ultrasound
An ultrasound offers a more precise way to estimate when conception occurred. Because fetal growth generally follows a predictable pattern in early pregnancy, measuring the fetus during an ultrasound can help estimate gestational age—and, in turn, the likely date of conception.
Ultrasounds also serve another purpose: confirming that the pregnancy is developing normally, ruling out complications like miscarriage or ectopic pregnancy.³
You can get an ultrasound through your OB-GYN, though this often involves appointments, paperwork, and insurance. Many pregnancy centers offer free ultrasounds in a more private and accessible setting.
Get Help Determining Your Conception Date
If you’re unsure when you conceived or have general questions about pregnancy, we’re here to support you.
Text (928) 832-4230 to speak confidentially with a licensed nurse. Whether you're looking to calculate your conception window or learn more about your options, compassionate help is just a message away.
Sources:
1. https://www.mayoclinic.org/healthy-lifestyle/getting-pregnant/expert-answers/ovulation-signs/faq-20058000
2. https://my.clevelandclinic.org/health/articles/23439-ovulation
3. https://my.clevelandclinic.org/health/diagnostics/9704-ultrasound-in-pregnancy