well when your puppy has a period its called ''heat''. it means she's in heat and that she can get pregnant.to help her i would be outside with her and keep her on a leash so she won't run off and get pregnant. I have a shih tzu to. shes had puppies once and shes adorable.
You need to watch her like a hawk. Dogs are very sneaky when they want to breed. They can't help it, it is a natural instint. It is your job to make sure it does not happen. Also call the vet to schudule her appointment to be spayed. Then you can help to prolong your dogs life without worries about future heat cycles.
He's your friend,your partner,your defender your dog.You are his life,his love,his leader. He will be yours faithful and true to the last beat of his heart.You owe it to him to worthy of such devotion
Please keep in mind that if you use the puppy panties or diapers, that these are meant to keep the blood or other secretions from staining your carpet, furniture, etc. and offer little in the way of protection from accidental breeding. As others have said, watch her like a hawk and keep her away from ANY intact male dogs, even male puppies over the age of about 4 months. Getting an unspayed female through a heat cycle can be a royal pain in the neck and other body parts, but it is your responsibility as a pet owner to take whatever steps are necessary. Please have her spayed after her heat cycle is over.