LEEP procedure and Pregnancy?

How many women have had a LEEP done and had any complications later in their pregnancy? I had one done about 2 1/2 years ago. I'm close to 30 weeks pregnant now. My OB did a transl ultrasound @ 16 weeks and my cervix measured 2.7 cm, and then again at 20 weeks and it measured 2.8 cm (she said possibly it lengthened a bit due to my bladder or jsut less stress). I'm just nervous about pre-term labor since I think they like to see your cervix above 3 cm and mine was shorter at only 16 weeks.I also heard the scarring can cause some problems with dilation during labor? What problems can/does it cause?