Final answer:
Presumptive signs of pregnancy such as weight gain, constipation, uterine cramping, and back pain can occur during the first trimester, but they are not definite proof of pregnancy. It's important to seek accurate confirmation through a pregnancy test or consultation with a healthcare professional.
Step-by-step explanation:
The signs and symptoms listed are presumptive signs of pregnancy, which means they are possible indications of pregnancy but not definite proof.
Some of the signs mentioned, such as weight gain, constipation, uterine cramping, and back pain, can occur during the first trimester of pregnancy. However, it's important to note that these symptoms can also be caused by other factors.
If someone suspects they may be pregnant, it's important to take a pregnancy test or consult a healthcare professional for accurate confirmation.