Big brother


I keep telling my 2 year old that hes going to be a big brother. Been telling him since i found out i was pregnant. I know he doesnt really understand yet but i keep telling him so it wont be such a shock. And so he knows to be gentle with mommy

My dilemma is that i have a friend who told me its a bad idea to keep telling because he has no sense of time yet. That 9 months is too hard to understand for him. Iv never told him in "x" amount of months, but i do tell him when the baby gets big, really really big that he/she will come live with our family and tell him to keep watching mommys belly grow bigger. Has anyone ever told you not to tell your kids about the new baby?