What should be the first step for a 19-year-old female, who is 38 weeks pregnant and was recently in a car accident, experiencing lower abdominal tightness?

Asking about prenatal care is the most appropriate first step in this scenario because it provides critical background information about the patient’s pregnancy history and overall health during her pregnancy. Understanding her prenatal care will help determine if there have been any complications, if she has had regular check-ups, and if she has received necessary vaccinations and screenings. This context is crucial in assessing the potential impact of the car accident on both the mother and the fetus.

In this situation, assessing the patient's prenatal care history can also help healthcare providers make more informed decisions about the next steps in management. For instance, if she has had a healthy pregnancy with regular check-ups, the next steps may differ compared to someone who has had multiple complications.

While monitoring fetal heart rate could be an important component of care after assessing her history, it is not the first step that should be taken. Performing an ultrasound or ordering a CT scan may also be necessary later but would typically follow an initial assessment of the patient’s current condition and prenatal history to determine the urgency and appropriateness of such interventions.