Hey V
Hope you have not scratched yourself into oblivion yet.
I have endured the same thing (admittedly I do suffer from eczema too - maybe you should be checked by dr before spending too much more on creams etc just in case it is a mild form of dermatitis apparently it can develop during pregnancy? )
Anyway - I have found the following things have helped:
1. Slather a layer of moisturiser or body oil (atm i am using hamilton body oil its in the itchy skin section of the chemist) before i go to the pool, it creates a barrier on the skin so the chlorine does not dry the skin out too much - i have been able to make it home to shower since doing this;
2. Cooler and shorter showers, pat dry and then moisturise whilst skin a little damp to try and retain the moisture on the skin;
3. On advice of naturopath - add flaxseed oil to diet - you can buy blackmores capsules to take with your vitamins or the oil in the bottle - if you buy the latter add a little to smoothies or on salad as a dressing. Try and eat a have some each day. Its a bit nutty in flavour, quite nice really. My skin settled alot when i started this (my hair is heaps more shiny too).
4. try and wear natural fibres which breathe and keep surface of skin cool and aerated eg cotton rather than synthetics.
5. Worst case scenario if you are struggling really badly you could go to chemist and buy over the counter polaramine tablets,they are class A therefore ok to take during preggo, warning they do make you sleepy but might be ok if you are finding your sleep is interrupted by the itch ie you could take one go to bed early.
Good luck
B