Linny, hi, I'm not having twins, but, even thou i have felt movement since 15weeks, they have not been regular, or very strong. Went like 2 weeks without feeling anything. The last 2 days only i have felt stronger movements.
They say they move more at night time, when we are asleep, as our daily movements rock the bubs to sleep, so at night when we are sleeping, and not moving, they tend to be awake. So we miss all the action!