Which physical examination finding is a normal occurrence during pregnancy?

During pregnancy, one of the normal physical examination findings is the bluish color of the cervix, known as Chadwick's sign. This sign occurs due to increased blood flow to the pelvic region and the cervix itself, resulting in a bluish hue. This change is a reflection of the vascular changes that accompany pregnancy and is typically noticeable around the sixth week gestation.

A firm cervix can occur due to various factors but is not unique to pregnancy and may indicate other conditions. Pale vaginal mucosa is usually a sign of decreased blood flow or anemia, neither of which is typically a normal finding during pregnancy, where increased blood volume usually results in a more vascular appearance. A closed cervical os is not definitive for pregnancy as it can occur in non-pregnant women as well, and monitoring the cervical os is more pertinent in assessing the risk of preterm labor rather than a sign of normalcy in pregnancy.