Ohhh exciting I'm 13weeks and can't wait for my daughter to feel her younger sibling moving :)
Twitch, butterflies or popping sensation are all baby movements. Great feeling isn't it :-) I'm 16 weeks and this evening my daughter was sat on my lap leaning back on me and I could feel baby pushing against her. My kid loved it :-)
Im ftm as well im 15 wks and it feels like lil popcorn in your baby area. Lol i thought it was gas at first:) shpuld be the bby especially if ypur 16wks