For someone asking that doesn't have children I would say nearly 4mnths, if they have kids I would say 16wks.. post about 5mnths I think I just stuck to months unless it was medical!
Definitely not a stupid question and I remember asking the exact same when my kiddo was around that age. I counted the weeks until around 20 and then switched to months as I found more stuff is aged by months from then. I always classed a month as on the date each month though from the start so although I'd say he was 16 weeks I wouldn't say 4 months till the date. I think there isn't a right or wrong though
Thanks everyone x
I would consider 4 months on the 5th. Just like birthdays!