Trust me, you'll fill your time with so much stuff that you'll wonder how you ever managed to cope with work too!! I had 6 weeks before my DD arrived and loved every minute of it! I finished little things around the house, cleaned for England uncontrollably, went for lunches and walks with people from my anti natal group, watched lots of tele and enjoyed it (not a big tele person, was very amazed at those people that go on Jeremy Kyle!!) ate, slept, shopped and just made sure everything was ready for baby's arrival! I cooked loads of dinners and put them into the freezer as I knew that when baby arrived I wouldn't be able to and husband would just make fried crap, not what you want to eat when your breast feeding!! And at least the kitchen wouldn't be completely trashed everyday!! Enjoy yourself! You'll love it!!
I had about 3 months! In the last 2 months I had one day where I felt only slightly bored, the rest of the time it's been brilliant. By the time i've got up and had breakfast and watched a bit of TV it's nearly lunch time. Some days I'll go shopping, do a bit of cleaning/tidying and cook something nice for DH when he gets home from work. Then there's ordering things for the baby online, going for walks, more shopping - as coppernoddle said, I honestly can't understand how I fitted in a full time job before. It's just great having the time off for those of us lucky enough to get it so relax and enjoy it, even if you don't do very much - you'll certainly be busy once baby is here!
you cannot have the house too organised - decluttered/cleaned etc or too many meals in the freezer in my view I liked going for antenatal exercise classes and meeting people from my antenatal classes do some grown up things with your partner - if he can have a couple of days off and you maybe go out for lunch that would be nice find out what baby groups/activities are going on in your area - and some welcome pregnant women so you won't have to go for the first time with a new born visit people who don't work in the week maybe?
Apart from the good advice others have mentioned, I have done the following - currently expecting no. 4 so been there a few times before : )
- get a haircut in the last 2 weeks before your due date. It does take a while after the new arrival to get another one! - get a pedicure. This may come from having my first in an Australian summer (now living in UK) but spending hours in labour sitting on a fitball staring at the floor it was nice to see at least my feet looked good each time. - go for a couple of meals out (doesn't need to be anywhere fancy or expensive) with DH without having to plan ahead, arrange/pay for babysitters and express milk.
Most of all enjoy just being able to walk out of the house with only having to lift a handbag : )
What everyone else has said...lazy lunches with friends, cinema, read books, sleep, tidy and declutter the house, attend to personal grooming - pedicures and bikini waxes are essential, as well as a good haircut/colour.
Bear in mind the early-days photos with the new baby. Get a bit of a tan from sitting outside/get a spray tan so the photos are good. Or make sure they are in black and white! Sounds vain, but they are photos you will look at a LOT.
Buy a couple of nursing bras/tops. Think beyond the birth to the first week with the baby and try to prepare for that. Cook and freeze some meals in readiness, and have biscuits and snacks for visitors in the cupboard, as well as tea, coffee and champagne on ice!