Hi Becky
I think feeling faint occasionally can be normal for a pregnancy - I get a bit light headed sometimes if I get out of bed too quickly, but I don't think it's normal to actually pass out. Also I thought it related mostly to blood sugar levels, in which case it should subside once you have something to eat.
If you're getting a temperature as well, or if the light-headedness has continued then I think I'd make an appointment to see the doctor to be on the safe side.
Good luck
LBxxx