I found when I cut off the television and lay on my back, I really feel movement below my navel. But only on my back for a few minutes, because laying on your back decreases blood flow, so I always try to lay on my sides.
I feel my baby move and im 17 weeks as well. I fortunately learned how it felt during a tummy check. When the Dr put the fetal doppler on my tummy we heard a swooshing sound and it felt like I had butterflies in the bottom of my tummy. My Dr said thats the baby moving around. He said I have an active baby all ready, and that really put a smile on my face.
i had felt a movement ONCE when i was 16 weeks that i was sure was baby and at the next Dr appointment my Dr asked if i felt anything, i said i thought i had and she shot me down and said it wasnt likely but i was a feeling like the baby turned and rubbed on the side... so i dono and it was for a couple weeks after that that i started to feel more... its so hard to know for sure... i cant wait till i can watch the baby move!! thats the best :)
If you think it's the baby, it more then likely is. It's a little early for your first one I think but it all depends on certain people.