I'm sure this must have been asked many times before but I'm being too lazy to search the archive.
I'm 17+4 with my second and don't think I've felt any movements - I've felt a few flutters but that could just be my digestive system. Last pregnancy I think I was 19 weeks before I felt anything; however, my midwife said I should expect to feel something by 18 weeks this time.
I'm just at that stage when I don't feel pregnant as I'm not really showing yet and have stopped feeling sick.