I have been pondering this same thing...
With my first, I actually felt movement externally as I was laying down at exactly 15 weeks, whilst my hand was on my tummy - it felt like something was lightly poking my hand. I would have thought I was just mad if my husband hadn't felt it too. I then felt movements internally from exactly 16 weeks - almost felt like little muscle twitches at first.
However, the placenta was posterior with that pregnancy, and now with my second I have an anterior placenta - which they say because the placenta is covering your tummy, you tend to feel movement later. So far, as of 15 weeks and 2 days, I don't think I have felt anything obvious yet. I did, once or twice, feel this odd sensation like maybe the baby was stretching out, and pushing my uterus out.. as it kind of felt hard-ish, and like it was pushing outwards.. but I honestly think my mind may have been playing tricks on me!
I am really hoping I don't have to wait too long to feel movement, as after 3 MCs, it would certainly be nice to feel that movement.
Certainly sounds like the fluttering feeling you've been having could be baby movements!