I stopped with the weeks after 12 weeks old, my son was born may 8th so 8th jan he will be 8 months x
Baby was born on the 22nd so every 22nd is a new month but I did it like you for the first few months unill I just started saying the month not the week
Say baby was born on May 1st, then the 1st of every month thereafter is when you will add another month to their age. So in this case baby would be 8 months. 9 months on 1st of Feb.