To stay or not to stay...

I am going to a conference for work, in October. I'm really excited, because it's in San Jose, CA, and I've never been to California before!! Now, before I got pregnant, I was planning on either going a day early or staying a day or two late. Now, I'm not so sure!! I know San Jose is like an hour to San Francisco (and the only reason I know that is from looking at flights), and I'm dyeing to get to Artfibers after seeing and hearing so many great things about their stuff. But the idea of travelling alone, in a big city like San Francisco, kind of freaks me out. Is it worth it?? Or are there any neat yarn shops in/near San Jose? I really know NOTHING about California, it's terrible! Any advice would be awesome.