Can a 7 month chihuahua have period?

No, a 7 month old Chihuahua cannot have a period. Menstrual cycles only occur in humans and some other primate species. Dogs, including Chihuahuas, do not have periods. Female dogs go through an estrus cycle, which is the reproductive cycle that makes them capable of reproducing. But it doesn't closely match the menstrual cycles of some other animals.