Hello
After my female puppy urinates she has this stringy mucus stuff hanging from her peepee area is this normal

No. Is she still young enough that you are going to the vet for shots again soon? If you will be at the vet in the next week or 2 mention it to the vet. You might post back with her age and other details.

Yes, and please let us know if she's spayed or not...

-Beth

I have a 3-4 pound female yorkie who is 8 months old. At what age can she become
Pregnant? When she bleeds, is it a lot to notice? Any experiences in that small of puppy?

Please get her spayed now. Call the vet tomorrow. She could come into season anytime in the next 6 months, but most likely soon. From your question, I can't imagine you have done the work needed to become a responsible breeder. Take a look at Should I Breed My Dog? Can you begin to follow those guidelines?

A small dog like that isn't going to have that much discharge, but must be protected from being bred. Responsible breeders never breed a dog before 2 years. She could become pregnant once she comes in season. It is very stressful for a dog to be bred when it is less than a year old. Please make sure it doesn't happen.