For loop keeps going

I isolated the problem but still can't see the problem with it, the turtle keeps going forward an extra 3-7 blocks randomly whether its mining anything or not. I did a little searching on Google and as far as I can see the repeat and for are written correctly it just doesn't work correctly.

function BlockTest()
   if turtle.forward() == false then
	  repeat
	  turtle.dig()
	  sleep(0.5)
	  until turtle.forward() == true
   end
end
for n = 1,10,1 do --[[ I added the last 1 just to rule out any chance that it was the cause ]]--
   turtle.dig()
   turtle.forward()
   BlockTest()
end

Well each time you call turtle.forward() it will try to move forward. Even if you're just checking to see that it can move.
So each time you're in a loop, it first digs, moves, then calls BlockTest (which first moves, and the repeat loop will move a third time)

try to just use something like:

function move()
repeat
  turtle.dig()
until turtle.forward()
end
for n = 1, 10 do
move()
end

Though I don't know if that's what you're looking for but it will at least work….