Change in CM? TMI warning!!

Katie
Hi, I'm ttc baby #2 and AF isnt due til the 13th. Yesterday I went pee and when I wiped there was a huge blob of snot like CM, with almost a yellow tint to it. I read online this could be the beginning of the mucus plug forming but I don't wanna read to much into it and be disappointed again. So has anyone had this happen to them? Were you actually preggo or no?