I looked back and on 7th March he posted he was 16 weeks and that would have made yesterday 22 weeks. Which is actually correct for 15th November birthday.
He’s losing count. Which I think around this age is normal and many go from counting in weeks to just months. But they think a month is four weeks.
Problem is if he thinks yesterday is 23 weeks and doesn’t realise his mistake, he will also think next week is 24 weeks = 6 months !! Not only will he not be six months, he also won’t be 24 weeks!! What a mess!! Imagine repeatedly getting the age of your own child wrong!!!