is this it?

Earlier today I went in to see my doctor for feeling really nauseous severe head aches, and occasional contractions. well he checked my cervix and said that since I went in on Monday it was 1 cm and 80effaced today it was 2.5 cm and almost completely thinned. about an two hours after I got home this came out when I wiped

that was at about 5 or 6. now since 7:50 I've been having severe cramps and my stomach feels super tight, and this fell out a few minutes ago

is this my mucus plug? am I going into labor?