Roll over and bowel movement

Ha....by today, I saw with my own eyes, Sebastian rolled over and lied on his tummy :-)
Days ago, his nanny had informed me that he started to roll over. but due to his chubby butt and head, he was unable to do that without assistance.
So, everyday, she gives encouragement and hands for Sebastian.
However, he is unable to roll back to original position yet
hoho....

one thing sits in my mind, he has no bowel movement for four days now.
when he was a newbie, his poop was several times a day, then slowly became once a day, once every two days and once every three days.
well, he did not look in pain doing it and his poop was in good shape too.
meaning, he should be in fine condition.
so, I started to browse around, to seek some answers if it is normal not to poop daily.
I have learned that formula baby and breastfed baby is different in this activity.
Formula baby usually does it daily, while not necessarily for breastfed baby.
This is due to fact that breastmilk is easy to absorp and stomach may do it very well that leaves baby nothing to poop out
At first, I though above rule should applicable to baby either with full formula and full breastfedbut it looks that baby with mixed formula and breastmilk will experience this too.

After all, I have consulted his pediatric about it and she said it is even ok to poop out once in a week. Ha... what a relieve.

He is getting chubbier than before.