Thanks for the query.
Some amount of weakness, tiredness
etc are common in pregnancy
and may increase with progression of gestational age
as the needs of the baby will increase.
But as you are having headache, body pains etc better consult your doctor once and check for blood pressure, blood sugar, hemoglobin
If she suggests better to go for thyroid profile once. As thyroid hormonal abnormality can present with some of these symptoms.