Mucus plug at 36 weeks!

I’m 36 weeks & 3 days. Went to my doctor two days ago and she checked me and I was 2cm dilated & 60% effaced. Now tonight after I peed, I think i lost my mucus plug! Is that what this is? and is that all of it? or is there more to come? There was a little bit more after this that came too. how much longer until labor starts after losing it?? After i lost it i immediately started feeling pressure in my liver pelvis. Thank you!