reduced movements?

im almost 30 weeks pregnant and i dont really feel much movement. i feel minimal movement early in the mornings then probably a bit throughout the day then a bit more at night time but i wouldnt say it was alot. i do have an anterior placenta but the movements are very strong so seems like if she was moving anymore i would feel them? should i be worried whats classed as reduced movements? this is my 4th baby so you would think id know but i just can remember much from past pregnancies. shes wiggling away as im typing this. its not a sudden change in movements shes been like this since i 1st started feeling them so im just a bit unsure is it just normal for her or should i be worried.