i felt my first movements at 18 weeks with my daughter. it felt like someone had gently poked me with a pen from the inside. and it was very low. i waited a few minutes with my hand in place where i had originally felt it, and sure enough the little booger kicked me again :) if you're guessing on what it is, it probably isn't fetal movement quite yet. you will know for sure when it is! the earliest i have heard of women feeling fetal movement is 16 weeks. but, every woman is different! soon enough it will wake you in your sleep, good luck!
it sounds like gas but sometimes thats what your baby feels like mine felf more like i had a gold fish flapping around at 1st now it feels like my uterus is stretching
If this is your first (depending on how far you are) it takes a longer time to feel it. And when you do it's not really consistent. It almost sounds as though it's gas, but I could very well be wrong. It would be my guess anyways.