Thankyou so much everyone for your replies. Since I posted I have started feeling movement and kicks! It started last week in the mornings, very light, almost like gas/wind!!

I realise now that I also felt it once or twic very faintly in weeks 16 and 17. On Tuesday the little one was going crazy and I felt like I could feel everything however I've not felt it so much in the last couple of days which, as you can imagine, has got me thinking all sorts! However I've just read in a good book that at this early stage you don't feel continous movement so I will have to learn to chill out!!
Macca wow that's amazing you've felt them move so early! Are you afraid of how big they're going to become? What a nice feeling - you'll either have stunning leggy supermodels or strapping handsome rugby players!, tee hee!
Em so nice to hear from you. an't believe you are 31 weeks already. How are you keeping?? I remember seeing a post when you were about 17 weeks and that seems like just a few days ago. It makes it feel like my own pregnancy will probably whizz by too!
Thanks again for everyone's replies xxx