Watch how John Hendrickson and Amanda Mammana are during their speech blocks. They are either closing their eyes or looking away. But it's ok to maintain eye contact, it's just that you might have to disclose what's going on, that you have a speech impediment and you are not pausing on purpose. If your secondary behavior includes frowning or eyebrows raising, then, from my experience, you definitely need to disclose your stutter at some point. It's the same reason that someone with a tic disorder that interferes with their facial or verbal communication must eventually disclose it. You could disclose verbally, or you could perform a bit of voluntary repetition stutter as a quick way of disclosing that you have a stutter without actually saying it. And you can just let throat sounds happen during blocks instead of trying to suppress it. That is another way of disclosing it.