I agree with Alan. When you first feel your baby it feels "swishy", "like butterflies", "like gas but you don't foof", "like bubbles popping". That stitch feeling is common and I think most women have it but it is generally thought to be the ligaments that support your uterus stretching. Some women get a sore belly button too as this happens... I have all three right now!

Good luck with it all - us Mamas play such a guessing game don't we... But it all sounds like things are growing beautifully...