Am I in labor??

So I’m 39w5d today and as of Tuesday I was about 2-3cm and 80% effaced..I had one REALLY strong contraction last night that took my breath away and all thru the night I was cramping. Woke up this morning and lost more of my mucus plug that was tinged with blood and I’m continuing to get cramps that are pretty strong but I wouldn’t say regular and lower back pain. This is my first baby if you can’t tell so I don’t know exactly what to expect !? Should I call my midwife or wait and see if I get more contractions?