Mucus Plug and Dilation

I'm 38 weeks and 2 days along, on Wednesday, a day before I became 38 weeks, I had my OB appointment. She said I was 1cm dilated and 75% effaced. Well, this morning I woke up and I DEFINITELY lost my mucus plug. I'm a FTM, so I didn't know if I would know when it happened, but I did for sure! Then nothing else has really happened today, but about an hour ago I went pee and noticed I'm losing more of it. I lost so much this morning, I figured that was it. Any ideas as to why I'm still losing it? Also, once you lost yours, how much longer until your little one arrived?