Did this happen to you too? (fetal kicks and movement)?

Hi..Im 4 1/2 months pregnant and this is my 3rd baby. I have noticed tiny tiny vibrations since about 12 weeks but nothing noticable. Now i have been feeling tiny little kicks *not flutters* more like kicks but very very soft and subtle *not very strong* in my lower abdomen right where my baby lay. the thing is i only feel them when sitting at my computer kinda leaning over in the chair or when my pants are rolled under my belly *so u could say when i have pressure under my belly* thats the only time i feel them. has this happened to you too? when will i feel them without having to bend my tummy down? i wanna be able to feel them while just lying down or sitting regularly. 18 weeks pregnant…