A4 B7 2.0TDi Low Oil Level Warning Light

Hi guys. 2.0Tdi with about 3500 miles....
I had the low oil level warning light on, checked oil, was slightly on the low side (the "may top up" area in the manual) ....topped up and still on....anyone had anything similar??? Faulty sensor???

Hi guys...thanks for the words.

Took the car to dealer (Wearside Audi) and at first the said that they would change the sensor. Went back in today (A3 2.0T as courtesy car....VERY glad I went for an A4) and they rang to say that indeed car was low on oil (after a week!!!) so it seems that the engine is using oil...

Is anyone else's 2.0TDi using oil...how much? I've done 4000 miles and it's used about 1.5 litres....