My figuring with this pretty much, if you can avoid it, like all potential risks, then by all means go for it, but, dont keep your self awake at night worring about how you are sleeping.
I reckon that's sound advice! I'm a back-sleeper and stressed out for ages when I was pg about sleeping on my back. It's not worth the stress! The risk is minimal, but if you are very worried, another good idea (I found it worked for me *some* nights) is to make a pile of pillows to lean back on so that you're semi-reclined, KWIM?
In any case, I would recommend sleeping however you are comfy for as long as you can... There'll be plenty of sleeping discomfort later on in the pregnancy ha ha