Following changes can be seen in the first trimester of pregnancy,$EXCEPT$:

$A$: The first sign of a growing foetus may be noticed by listening to the heart sound through the stethoscope.
$R$: By the end of the second month of pregnancy,the foetus develops limbs and digits.

The literal meaning of "gastrulation" is

High increase in $oxytocin$ level in a pregnant lady results in:

When do the first movements of the fetus and the appearance of hair on the head usually occur?

In human beings,after .............. month of pregnancy,the embryo's heart is formed.