I found I never got the whole daily routine of movements the books tell you to expect - I have days where Ed is either really active, or quiet. I was told that so long as you get 10 or more movements a day, its probably fine - although having an anterior placenta you could be having heaps that you're just not feeling.

Ask your OB/midwife next time you have a check up if you're concerned, and maybe keep a little chart of when you do feel them.