You are not required to perform the Prostration of Forgetfulness

Question :

I always pray, but I always forget and am in doubt over how many Rak'ahs I have prayed and how many remain, for this reason, I often make the prostration of forgetfulness - is this permissible?

Answer:

You must take care to be attentive in your prayer and make sure that your heart is in it, and there is no requirement to perform the prostration of forgetfulness simply due to the whispering of one's self. If you are in doubt over whether you have left out a Rak'ah or some (other) pillar, then perform it in order to be sure, and make the prostration of forgetfulness.

Read more:

Remembrance Aloud after Prayer is a Sunnah

Question : What is the ruling on raising the voice when seeking forgiveness and ...

The ruling on burying the Deceased at Night

Question : If a person dies before midnight or after midnight, is it permissible...

Passing directly in Front of a Worshipper in Prayer

It is forbidden to pass directly in front of a worshipper in prayer, whether he ...

The Ruling on drying the Limbs after Wudhu

it is permissible for a person to dry his limbs after making Wudhu', and likewis...