IMO as long as you know what they are, there is so reason to be concerned about them. Fear and not knowing what you are experiencing always makes things worse.
Also if you aim to get your LDs through MILD, DILD and WBTB (hover mouse over them to see what they mean) you have the same chance of having SP as a normal dreamer.
(have you read the big sleep paralysis and old hag topics in the stuff of dreams forum? We are upto part III now (Part I 
Part II 
Part III)