Not sure how she can tell you you'll never faint. I've had the same symptoms and have fainted twice.
It's not a minor thing, and can have potentially serious effects.
IF it's low blood pressure (and that's not to say it is) then there is less oxygen getting to your organs, in extreme cases it can cause a heart attack or you to go into shock, as well as possible kidney damage.
Other things it could be include anaemia, hypoclycaemia (however you spell it!) and even diabetes.
I spoke to a few medical people I know unofficially, and against their advice have decided to stay on the diet a little longer. I plan to go into RTM a little earlier though.
The decision is up to you, it's your health and your life!
I made the decision to take a risk (albeit a relatively small one) with my physical health, for the benefit of my long term health (being overweight is hardly a healthy lifestyle option) and my mental health (being big has stopped me living) but it was not made lightly.
I was very disappointed with the way my LLC dealt with it, playing it down as though it is nothing to worry about. The chances are I will have no lasting side effects, BUT it is certainly not risk free.
Make your own choice, but do a bit of research, maybe speak to a doctor (and have blood tests if necessary) but make it an INFORMED choice.