FTM-labor?? Back pain and shifted to abdominal pain?

Caroline

I am 39 weeks and 6 days. I noticed period like cramping this whole week however now I am experiencing much more intense back ache pain and now lower abdomen pain. I just lost my mucus plug earlier today. The cramps are coming at regular intervals but have not increased in pain yet or feeling them all over my belly. Is this the start of labor?