Stormyduck

Hi all…long time lurker, first time poster. Anyway, bit of advice. Got in the car tonight (2013 Fabia Monte Carlo TSi) and the brake warning light came on with 3 beeps (higher pitched than the standard beeps) No ABS warning or anything else. However, when I moved off (I park on a slope) and got on to flat ground, it turned off. Driving was fine, and brakes felt fine. New brake pads and discs were put on in august. Would I be right in thinking that the most likely explanation is that because I’m parked on a slope and the brake fluid is low, the fluid tilts away from the sensor, triggering the warning? Booked in for a brake fluid change at the weekend just in case but just need some reassurance that my hunch is right