Hi lsharp, I can't really advise re the weeing side of things as I had a catheter and was kept in hospital for three days as I couldn't wee atall after the birth of baby Nat. However, what I did find strange was for up to about six weeks after the birth I was sweating loads at night time, I would wake up with cool skin but drenched in sweat, even on my calves, and having to change bedding daily because it was soaked.
(I'm painting a really nice image of myself aren't I? lol)
Anyway, I mentioned it to my midwife / health visitor and she said that it was completely normal and this is how your body rids itself of the extra fluids carried around during pregnancy. So if you have been experiencing this too then maybe you are not weeing so often because your body is sweating out the extra fluids?
Are you breastfeeding? As while I was breastfeeding I would drink 2 litres of water a day and find it was still not enough.
Is your wee concentrated when you do go?
Mention it to your health visitor / GP. GP is probably best bet, but HV might have some knowledge if it is what I described.