Rain - what exciting news - congratulations! You will have such a lovely time planning your first Christmas together (as well as welcoming your new baby of course)!
Mrsmadevans - I had a similar coccyx injury a few years ago. I slipped on the bottom of our stairs on Boxing Day - of all days - putting away Christmas presents 
. I only fell down 2 steps but the pain was excruciating and I thought I was going to pass out. The following day I had to make a 4 hour train journey to visit my parents and I did the whole thing kneeling on a seat as I couldn't sit down. Everyone told me to go and see a doctor but I was so embarrassed at the thought of having my arse x-rayed (I had visions of having to sit on a photocopier-type machine), plus I figured they probably couldn't do much about it anyway so I hobbled on. The pain lasted well over a year. Even now - 3 years later - if I sit in a particular chair it hurts...Just as well I have so much natural padding!
Not much Christmassing going on around here at the moment. DS had his birthday party this weekend so am still very much in recovery mode from that, trying to find homes for another round of presents (both the DCs have January birthdays so it gets a bit full-on, especially when you add in party presents) and trying to fit in some work today in between.