I think the fetus doesn't actually have spontaneous movement until 9-10 weeks, but after that, I'm quite sure you could feel it if the anatomy is right. Sometimes the baby is implanted back really far towards the back, but otherwise, I'm sure you can feel it this early! I first felt DS at 13 weeks, and that was my first pregnancy. I haven't felt anything yet but I'm only 10.5 weeks.
Sleepy mom of two (DS-11, DD-8). 5 lost: 9/2004, 3/2005, 4/2013, 8/2014, ectopic- rupture @7w, lost right tube 11/14