A 32-year-old woman comes to the emergency department with painless vaginal bleeding that began earlier in the day. She is at 36 weeks gestation in her 3rd pregnancy; she has had one previous full-term delivery and one spontaneous 1st-trimester abortion. She noticed a small amount of brown discharge on the toilet paper while wiping this morning. Later in the day, she noticed dark red blood on her underwear and decided to come to the emergency department. She denies fluid discharge, abdominal pain, or cramping, and she is feeling usual fetal movement. She has had no abdominal trauma. She has received all routine prenatal care and reports that everything has been normal until now.