How did you know you were in labor?

I am 38 weeks pregnant with my 2nd child. The 1st baby, I was induced at 40 weeks and I was 1cm at the time of induction. This time around I am having more signs that labor is near such as pelvic pressure, back pain, and pooping more often(tmi). I am wondering how soon will I go into labor? Did you have any similar symptoms if so how far from labor were you