sleeping throw the night??

Jessica • Im 26 and this will be my second pregnacy

I know all baby's are different but I feel like anyone I've talk to that has baby's theirs sleeps threw the night. My son is 8months old and for a short time he'd sleep till 5/6am which was great then eat and go back to sleep most mornings for bout 2months now he wakes up staring at ( goes to bed between 730-8) 12am ,2am .and the 6 or 7am where were up for the day this week he names once and only for an hour. nothing has changed in his schedule as far as I know. Am I the only one that 8 month doesn't sleep?