Movement at 12 weeks??

Lauren
Okay, so this is my second baby so I definitely know that what I am feeling is the baby, and not just wind lol
I have felt the little flutters for a few weeks and I just thought maybe that would be just wind, but now the feeling has changed to a kind of squirming.. And I feel it on both the left and right hand side at different times during the day.
What are people's thoughts? 
When I was pregnant with my little boy (now 2) I don't think I felt movement until a lot later. 
Is early movement a sign of twins?