Not feeling much movement

Hi there. Im 30+6 weeks. Anterior placenta. Some days I feel my.baby moving like crazy. Some days not at all. I feel like this far along, I should be feeling stronger kicks each day but feel like they are getting weaker each day. I dont want to over react as Ive already been to the hospital once because of decreased movement and he was absolutely fine. But feel so nervous and not right. Advice? I do have a doppler and he sounds ok. But i dont want to be using it all the time and have gone from feeling like i can use it once every week or two, to feeling like I need it on my belly all day to feel reassured. (Which I havent done but feel like I want to)