Is decreased fetal movement sometimes normal?

I'm 31 weeks pregnant with my little girl. I have PIH, but my bps have been great as of lately and no major swelling or pre-e red flags. (Had pre-e and HELLP last pregnancy, though).

I noticed my baby not moving as much as usual today. I did an hour long kick count tonight, laying on my left side and noted 5 movements. So I drank some juice and I'm sort of waiting to see if the kicking picks up, but so far nothing.

I'm not, in my gut, worried. I think she may just be in an odd position. I have an anterior placenta, so that could come into play here. Also, my stomach looks SIGNIFICANTLY smaller today - my husband even noticed. So that also leads me to believe she is in an odd position. The few little movements I felt during the kick count were down very very low - so perhaps she dropped?

Here is my plan, and I'd really appreciate feedback to know if this is reasonable. I'm doing another official hour long kick count tonight. I'll also do one in the morning. If she fails these, I'll call the doctor in the morning. (If she stops moving all together in the kick count tonight, I'll call tonight... but I think she is giving the odd kick here and there... just decreased movement over what is typical).

Am I over-reacting? Under-reacting? The nearest hospital (which is where I'd have to go if I went in tonight) is well over an hour away. I'm exhausted and would prefer to just go to bed... but obviously if this IS a real cause of concern I'd go in tonight. I guess I just don't know the significance of decreased movement, and if it can sometimes just be normal or due to baby being in an odd position.

Thanks for your input!!! I'm feeling lost.