How do u know when u lose your mucus plug?

Adina • I`m 24 with a 2 year old boy and another on the way. Married for 3 yrs.
I'm 25+4 and I just used the restroom. A long string of yellow mucus stuff was in the toilet . I didn't know until I looked down. What is it? I'm kinda freaking out. The baby is kicking still and I don't feel diff but when I looked up mucus plug pics it looked like mine. Was it just discharge maybe?