When Did I Conceive?

So, you’re pregnant. But on what date did you conceive, and how can you know who the father is? Need answers now? Chat anonymously with a nurse for free at (386) 384-8088.

While pinpointing the exact moment of conception isn’t an exact science, tracking your cycle can help you estimate when it likely occurred.

What Date Did I Conceive?

No matter how far along you are—whether 2 or 20 weeks—you can use a simple calculation to estimate your conception date.

On average, ovulation occurs about two weeks after the start of your last period, lasting for two to three days. This is the window when pregnancy is most likely.

Conception Date Calculator

By counting back from your last period, you can estimate your ovulation window and approximate conception date.

If you’d like a more precise estimate, free online conception calculators can help—or feel free to text us at (386) 384-8088 for assistance.

Keep in mind that every woman’s cycle is unique. Ovulation timing varies, and sperm can survive in the body for up to five days, meaning conception can sometimes occur even if intercourse happened before ovulation began.^{1, 2}

Conception Calculator

First Day of Your Last Period:

Average Length of Cycles:

Conception Date from Ultrasound

Another way to estimate your conception date is through an ultrasound. Since fetal development follows a consistent growth pattern, measurements taken during an ultrasound can provide a more accurate timeframe than an ovulation calculator.

In addition to estimating conception, an ultrasound can also confirm the health and viability of the pregnancy, ensuring it is developing properly and ruling out concerns such as miscarriage or ectopic pregnancy.³

You can schedule an ultrasound at your local OB-GYN’s office, though this typically involves paperwork and billing. Alternatively, many pregnancy centers offer free ultrasound services, allowing you to receive care without involving hospitals or insurance.

Get Help Determining Your Conception Date

If you're unsure about your conception date or have general pregnancy questions, we're here to support you.

Text (386) 384-8088 to connect with a certified nurse who can answer your questions and guide you through your options.

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