I am 37 weeks pregnant and 2/3 cm with soft cervix how long for labor?

It depends: There are so many factors in this question. Is this the first child? How long have you been 2/3 cm? And there is a lot of variability. As much as i hate to say it, there is no way of telling how long your labor may be, from 2-3 hours to over 24 hours. For children 2, 3, 4, etc.... That time will likely diminish. First children can be very unpredictable.