Thanks AlR - hopefully it won't present any problems when you go but it is interesting to find out. I know a friend of mine had dangerously low blood pressure when she was pregnant but never found out how it actually affected her, as you say the most usual is high blood pressure and the symptoms for that are more well documented.

I'm sure you're going to have a great trip nonetheless, it seems the more problems people have the more they appreciate having a good time etc. whereas some people have nothing to worry about and find fault and criticise every little thing.