Ay, usually around 16-20 weeks pa ang unang flutter, lalo na kung first time mo! But honestly, a few of us moms sa circle namin ay nakaramdam na ng something light around 14-15 weeks, parang gas or butterflies lang talaga, kaya madaling ma-dismiss. It really depends on kung saan ang placenta mo and kung gaano ka-sensitive, pero if you're feeling something different sa belly mo, best to mention it sa next check-up para sure lang.