I started fasting before they become fard on me may b from age 4 or 5.Will they balance the fast of the days i have missed for eg due to periods?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

First of all, we congratulate you for starting fasting and being keen on performing acts of good deeds at that early age, and we hope that Allaah will reward you.

It is confirmed in the Sunnah that a child is rewarded for the acts of obedience which he performs, like purity, prayer, fasting, Zakat, Hajj and the recitation of the Quran, and other acts of obedience as stated by the jurists . Nonetheless, these acts will be considered as supererogatory acts of worship but not as obligatory acts. If a child performs Hajj, his Hajj is acceptable and correct, but when he reaches the age of puberty he is obliged to perform Hajj again and the supererogatory Hajj is not sufficient for him. Similarly, if a woman fasted when she was young, her fasting is acceptable, but this is not sufficient for the obligatory fasting after she becomes pubescent. This does not replace her obligatory fasting or making up for the days she missed.

Therefore, you are obliged to make up for the days you broke the fast in Ramadan, as it is not correct to count the days which you fasted when you were young against the days you didn’t fast in Ramadan (when you became adult).  

Allaah Knows best.