Thanks for your replies:

Alan- nope I've never had that happen before which made me think at the time that it didn't seem right.

I've just been for a walk and I've been having contractions every half hour or so. Baby has completely turned and resumed the cephalic head down position that she was in for 3 weeks before yesterday happened. When I push on the top of my tummy its stings 'down there' so I'm assuming that is her head pressing on something down there.

Argh, why can't there be a little button that pops, kinda like a turkey that says 'ok I'm done prepare for take off'. I'm going to wait it out a bit and see if these contractions increase or anything else happens then I will give the midwives a call.