As a side note, its not usually necessary to top off your brake fluid unless it drops down below the min mark. As your pads wear, more fluid is pulled down into the system to accomodate pad wear. If you top off the fluid, it will only overflow the system when you compress the caliper pistons to replace the worn pads.
If it was at the max mark when the pads were new, and it isn't below the min mark; just keep an eye on it so it doesn't drop below the min mark. Once it gets near the min mark, also keep an eye on your pad thickness, as that means they are probably getting pretty thin. If the line drops below min, it means you have a leak or are losing fluid somewhere, as the capacity of the reservoir between min and max should accomodate pad wear from new to fully worn, plus some margin.
