galaxymum - that all sounds very exciting!!
I am, at the moment, more thick than usual so please bear with me!!
I put on 18lbs carrying my twins.
I didn't find out I was having twins until I was 10 days away from delivery (delivered at 38 wks - 1981 so routine scans werent done.)
I cant really answer the second question about if one moved more than the other. I was just told I was having a single baby that weighed around 10lbs!!! Sometimes the 'baby' moved so much it would shake me about.