Sorry but I have no experience with placenta being anywhere but in a good position, but just wanted to say that even tho I could feel movement at 21 weeks it was very inconsistent and I worried myself silly if I went half a day without feeling bubsy move. Now, I am almost 32 weeks the little bugger doesn't stop So, I say go get it checked for your piece of mind - I did when 22 weeks as I thought I hadn't felt anything for a couple of days. Its very true that they move and you don't feel it, around 26 weeks the baby was doing a back dive on the monitor (whilst having a scan) and I didn't feel a thing!! I am sure you will be fine hun xxx