Final answer:
Probable or presumptive signs of pregnancy include a missed menstrual period, tender nipples, increased appetite, frequent urination, nausea, vomiting, and weight gain in the breasts and abdominal region. These signs appear in the first trimester and are indicative of physiological changes due to pregnancy.
Step-by-step explanation:
Probable or presumptive signs of pregnancy are early indicators that a person may be pregnant. These signs can be noticed by the pregnant person before pregnancy is clinically confirmed. During the first trimester, common presumptive signs include a missed menstrual period, tender nipples, an increased appetite, and more frequent urination. Nausea and vomiting, colloquially known as morning sickness, are also common. Other changes that occur are weight gain, particularly in the breasts and abdominal region, as well as an increased sensitivity to odors. Pregnant women may also experience digestive changes and a rise in maternal blood volume and respiratory minute volume.