Final answer:
Pregnancy can be confirmed by signs including a missed menstrual period, tender and enlarged breasts, morning sickness, and increased urination frequency.
Step-by-step explanation:
Four positive signs of pregnancy a person might experience, especially in the first trimester, are:
- A missed menstrual period, which is often the first sign someone might notice.
- Tender and enlarged breasts as a result of hormonal changes.
- Nausea and vomiting, commonly referred to as "morning sickness," though it can occur at any time of the day.
- Increased frequency in urination due to changes in the body's physiology.
These signs are associated with the hormonal and physiological changes that occur in the body to support the growing fetus. Healthcare professionals can confirm pregnancy through a positive pregnancy test and prenatal care should commence shortly thereafter for the health of both the mother and the baby.