In the publication "Accuracy of self-assessment of gestational duration among people seeking abortion," we asked people seeking abortion a series of questions about how far along they thought they were in pregnancy. We then compared their responses to their gestational duration on ultrasound.
We asked commonly used questions such as "When was the first day of your last period?" as well as other questions such as "On what date do you think you got pregnant?" In addition, we included questions frequently used to screen pregnant people for eligibility for medication abortion (for example, do they typically get their period once a month?). Below, you can see how these questions work at identifying people above or below 70 days (or 10 weeks) gestation, the current FDA limit on medication abortion. Select the questions that you (or your patients) can answer.