People have described the amount of mucous earlier in BB as about 1/2 a teaspoon. When you see it, there is no mistaking what it is and mine was actually red and not watery pink which the m/w said was normal. So it is substantial enough to know.
Also, I lost mine 8 days ago with nothing happening since. You can lose it weeks before labour and also lose it a couple of times, I was told today by the m/w!