
Count the first day as the first day you saw blood, and keep her away from all other dogs for at least 21 days. After that time, if she looks as though she's over it (her vulva will have shrunk back from its massive 12-day(ish) size, but never back to its previous pre-pubescent size) and there is no discharge at all, blood-stained, straw-coloured or clear) then give her a good bath and wash all her bedding to remove any trace of scent. Then get her spayed three months after that. :)
During her season expect the discharge to get heavier (although it might not) and never let her out of doors unattended, even in your own garden.