my babyis sleeping around 20 hours a day from past two days. he is 3 months 10 days old is it normal?

A. Sleep Cycle in smaller babies is very different and they have a certain pattern initially which becomes regularize at around 6 to gy8 months of age and if the baby is comfortable with no irritability because of infantile coylic nasal blockage any regurgitation etc you should not worry just give a comfortable position to the baby and no medicine is required.