Early movement... Baby #2!

So according to the due date calculator I'm about 8w2d... Tonight I felt flutters in my lower Abdomen where the baby would be. This is baby number two and I know you can feel earlier movement, but this early? I've googled it and read where it could be possible, could be that I'm further along than I think, could be twins?, or could be gas?... Just felt different than gas. And from day one I've been thinking I could possibly have twins. So I'm freaking out a bit lol.. I'm sure it's not it.. But wondering if anyone else is going through this or could give some feedback with their opinion :)