cat in heat/ peeing problem

hi,
my kitty is normally fine with her litterbox but has suddenly started peeing at the opposite end of the room. I took her to the vet and she's clear from any UTI, and he suggested she's in heat. I am planning to get her spayed soon, but for the time being I'd like to know if once she's out of heat, will she go back to peeing in her box, or is this likely to be a persistent thing? I'm thinking of getting a second box, but i'd prefer not to!

my cat does the same while in heat but when shes out of heat she stops! so i reckon yours will too, think yourself lucky she dont do it on your bed!! mine does!!! not nice!!!!