I am 8 weeks pregnant and haven't had a bowel movement in more than 2 weeks, I am very uncomfortable, I have been drinking water eating fruit and fiber, but still nothing. Is it safe to use an enema?

Is your doctor aware of your situation? If not then they should be. At this point because of being pregnant 2 weeks is a very long time and you could be having other things going on. See your doctor before attempting anything please. If your plumbing is backed up it could be that the walls are thinned out and in attempting what your asking about could cause an accidental rupture.

This is no time for that. Please be careful and see your doctor.