Tan, I worried a little earlier on in my pg too. I didn't notice my little man moving nearly as much as his sister did and it is all in my pelvis, even now when he has turned and is the 'right' possie. I think some of it has to do with the fact that we don't have the time to take as much notice of bubs moving cause we are running after toddlers. I noticed and noted just about every movement with DD.
This time, I just don't really get much of a chance to sit and marvel at the miracle it is! The past few weeks though I have had some beautys right in the cervix and hip bones...reassureing but not very pleasant . I also think my placenta might be up the top of my uterus, kind of under my ribs because I don't really feel any movement there unless bubs is doing acrobatics or palying soccer or something inside me!
Try not to worry, I think it's only after you don't feel any movement at all for a significant amount of time, like over a day, that you need to worry. But as the other girls have said, go to the dr to have a listen of bubs hb if you need to, it's better than worryig your pants off for days.