My excuse is that I have SPD, and have been told by physio to do nothing more than a gentle 20 minute walk once/twice a day - DP even does the hoovering for me now 
I have been eating like an absolute pig, every day sees numerous amounts of chocolates (given as baby/engagement gifts!) homemade baked goods, biscuits etc being eaten. Like kirsty I've always been slim built, and never had to watch what I ate, I've found that now I'm 28 weeks, I've not really gained too much weight, it's all just gone a lot flabbier as I've lost the tone from walking the dog/riding.
Not riding is very very hard!! I had to give up work, so my horse went on loan, which is a relief as I'm not having to worry about mucking out or the costs of livery etc. But it's awful not being able to ride my friends horses - am worrying he'll end up giving the ride to someone else and I'll be lost! Only 12 weeks to go now though till my little arrival, am hoping to get back in the saddle as soon as possible, although having the SPD makes that a lot less likely!
TBH I'm just mega bored now. Am not working, can't walk the dog very far, yo uwould expect the house to be spotless am I'm home all day, but there's only so much housework a girl can do before she goes crazy! Am now considering washing and replacing the bedroom and living room curtains just because....
DP got up at 3am last night to watch the Utd match, and woke me up this morning telling me how excited he is now for the next season, it's a good job I love him 