Stupid argument

My husband hasn't been to all the antenatal classes I have, hasn't read and books blogs or email newsletters on pregnancy, birth / babycare.
He asks me questions sometimes and expects me to know the answer. If I don't know I can always look it up for him.
Last night he wanted to know what stage to go into hospital for the birth. I couldn't remember the exact timings for contractions so I googled it, read out what the nhs website says, wrote it down and pinned it to the fridge.
Later he says I told him that we don't need to go into hospital unless my waters have broken. I said that isn't right and that babies can be born with  the waters unbroken. I told him I didn't think that was what I said.
He said he can't trust anything I say because I keep changing my story and that he thinks I read a load of blogs whose content is not to be trusted so nothing I said would make him believe I was now giving him the right information.
This seems yo happen a lot where he tells me I said something I have no recollection of saying - things that are glaring obviously not true and seem unlikely to be from me. It is very frustrating because I can never prove what I actually said. I might have mispoken as my words occasionally  come out muddled, but then he might have misheard / missinterpreted / misremembered something too!
He went all huffy and stormed off, then sulked through dinner :-(