No. When you are not thinking about a pink elephant you are not doing the very action of not thinking about it, but what you are actually doing is thinking about something else. There is a difference between «not doing» and «doing something else». You get it? In relation to stuttering you have to think about something else. In a conversation that means thinking about (being present in) the actual conversation. When not in a conversation you should just go by your day. Don’t worry. And this goes for any other anxiety too.