Most people start to feel movements somewhere in the second trimester, and these become more regular as pregnancy progresses. There is no set 'normal' number that fits everyone; what matters is your baby's own usual pattern. Movements should not reduce toward the end of pregnancy.
A noticeable decrease, change, or absence of movements can be an important warning sign that the baby needs to be checked. It is a myth that babies move less near labour or that they simply 'run out of room'.
If you think movements have reduced or changed, do not wait until the next day and do not rely on home gadgets to reassure yourself. Contact your midwife or maternity unit immediately, at any hour. They would always rather check than have you wait. Repeated episodes also need reporting even if previous checks were normal.