It is quite difficult to estimate the amount of fluid you put out. It is not just a matter of checking how much you pee, you also lose a lot of fluid in your poo when you breathe and sweat.
Wanting to pee often but only managing to pass a little is very common late in pregnancy. Your baby is now taking up quite a bit of room in your tummy this leaves little room for your bladder to expand. Because your bladder cannot expand like it used to the sensors inside your bladder that tells your brain you need to pee are stimulated much earlier than they normally would and therefore you feel like you need to pee but are only able to pass small amounts.
It all sounds quite normal to me.