mucus plug? labor...

Julia • I'm just a girl living in a world full of hate

so I have lost alot of my mucus plug today and yesterday I am 39 weeks and 4 days pregnant. I have been cramping and after I had sex tonight I hoped in the shower and my stomach tightened for 1min twice. this is my first baby. I went to the doctor on Friday and I was 2.5 centimeters dilated. Could I be close to going into labor.