When Did I Conceive?

If you’re pregnant, you may be wondering when conception occurred and how to determine paternity. While pinpointing the exact moment of conception isn’t scientifically possible, your body follows natural cycles that can help you estimate when pregnancy began. Need answers now? Text anonymously with a nurse for free at (360) 328-7049.

What Date Did I Conceive?

Whether you are just a few weeks along or further into your pregnancy, you can use a simple calculation to estimate when conception likely occurred.

Ovulation—the time when an egg can be fertilized—typically happens about two weeks after the start of your last period. Since sperm can survive in the reproductive tract for up to five days, conception may occur from intercourse that happens before ovulation.^{1, 2}

Conception Date Calculator

By counting the days from your last menstrual period, you can estimate your ovulation window and, in turn, your conception date.

If calculating this on your own feels overwhelming, free online tools are available to help. You can also text us for guidance at (360) 328-7049.

It’s important to note that menstrual cycles vary from person to person. Some women ovulate earlier or later in their cycle, and some may have a longer or shorter fertile window than average.

Conception Calculator

First Day of Your Last Period:

Average Length of Cycles:

Conception Date from Ultrasound

Another reliable way to estimate conception is through an ultrasound.³ Since fetal development follows a consistent pattern, ultrasound measurements can provide a more precise timeframe for when pregnancy begins.

Beyond dating the pregnancy, an ultrasound can confirm fetal viability, ensuring that the pregnancy is developing as expected and is not ectopic or miscarried.

While ultrasounds are available through OB-GYN offices, they often require insurance and paperwork. ABC Life Choices offers free ultrasounds, providing a convenient and confidential option.

Get Help Determining Your Conception Date

If you have questions about when you conceived or need more information about your pregnancy, we’re here to support you.

Simply text (360) 328-7049 to connect with a certified nurse who can help you understand your options and next steps.

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