The only difference between my twin pregnancy and my singleton ones was that I fainted heaps when pregnant with twins. Morning sickness was no worse, neither was the exhaustion of early pregnancy. I showed early with all my pregnancies, and wasn't that bit until the 2nd half of my twin pregnancy. In fact I had seen heaps of midwives, who all palpated my belly, and all missed the twins until the 21 week scan because there was no outward sign that it was a buy-one-get-one-free pregnancy.