Hi xiscaioss, my doctor told me the same thing. When I was first diagnosed, I was with a partner right before my first outbreak. When I went to get a second opinion and ask questions to a doctor, he told me that I can't pass it along if I'm not showing symptoms and because my partner's immune system is strong, he would be OK. My partner was tested and his results were negative.
I've done some research on shedding and I am unable to find anything that says how we can tell when we are shedding. I've also found conflicting information about this so I'm still unsure. Please keep me posted if you find anything as well.