Final answer:
Fatigue, nausea, and vomiting, often labeled as morning sickness, are common signs of early pregnancy and subside usually around week 12. Fetal movements palpated by an examiner, known as quickening, become noticeable around weeks 16-20 and are a probable sign of pregnancy. Braxton Hicks contractions can occur but are not a specific indication of pregnancy as they may also happen outside of pregnancy.
Step-by-step explanation:
The signs that could indicate pregnancy vary as the pregnancy progresses. Fatigue, nausea and vomiting are common in the first few months and are associated with the increased levels of pregnancy hormones like estrogen, progesterone, and hCG. These symptoms are often more intense during the first trimester and can be profound enough that they are noticed even before a missed period. They're typically referred to as morning sickness, though they can occur at any time of the day. Nausea generally subsides by about week 12.
By the second trimester, around weeks 13 to 28, the mother may feel more energized, and the previous nausea and vomiting often subside. Additionally, around weeks 16-20, she might begin to feel fetal movements, known as quickening, which is a clear sign of pregnancy. Braxton Hicks contractions are also possible but are more commonly experienced in the later stages of pregnancy, serving as a prelude to labor by toning the uterine muscles. However, they are not a definitive sign of pregnancy as they can also be experienced by non-pregnant individuals.