Mucus plug?

Jane • Currently pregnant with my first baby. 🌸👶🏼🎀 She's a girl!! Due October 12th 🏩
I am a ftm. I have a few questions about the mucus plug. 
How far along were you when you lost your mucus plug?
How did you know that it was the mucus plug and not just discharge?
Did you lose it all at once or pieces at a time?