I'm a super newbie so if there's anything I'm doing wrong as far as posting please let me know. I love this community and I can't wait to join in on all the Yorkietalk

My teacup yorkie is Cruz (pics Below) and he is officially 9 weeks today. He has had his first round of shots. He has been out of the house with me just walking while I hold him a little but I'm afraid to sit him down on the ground for 2 reasons:
1. He hasn't had all his shots and I'm afraid he will get some nasty virus or catch something bad from the other dogs in our neighborhood.
2. He is less than one pound and extremely tiny. All the dogs in our neighborhood are huge and loud. Although he has a harness and a leash I'm worried about him being in danger. He is expected to get to about 3lbs full grown based on his parents. My last yorkie was around 9lbs when he passed at 6 years old and he grew to full size pretty fast. I know Cruz Cayden will be tiny but maybe I'm just paranoid. Anyone else with tiny yorkies: When did you let your baby outside on a leash for walks?
Thanks everyone! Here's Cruz Cayden below:
2013-04-26201903_zps40a41adb.jpg 2013-04-27002909_zps3b0ff85f.jpg 2013-04-26224453_zpsc1e66a76.jpg