If you are living seperate from your partner and not working yourself then I urge you to claim income support. You can apply for lone parent (as you are not living together) which is around £54 a week and once you have claimed this you can also get a surestart maternity grant which is a payment for the baby of £500 which you don't pay back.
Once the baby is born you can also claim child tax credit which is around £87 a week and child benefit is £15.
Your next step should be to go to your local jobcentre and ask them. If you have anymore questions please feel free to pm me as my best friend is claiming these benefits so I can tell you most things you want to know.
Good luck!