I didn't feel Quark until 19ish weeks easy...which was very disappointing for me because I felt Spock insanely from about 14 weeks. The reason for this though is this time I have an anterior placenta, and even when I do feel Quark it is light and muffled...not the hard strong boots I would get from Spock. I'm now 26 weeks and have only I. The last week noticed my belly move or felt a strong boot. But still I can go hours without felling anything, with Spock she never sat still!! It is sad, makes me really focus and hang on to what I do feel, hoping it gets more and stronger, but damn those anterior placentas!!