Since you are pregnant and not yet term, you cannot use laxatives as they are going to cause uterine irritability. Instead, you may modify your diet and try to add lot of fiber and increase the intake of fluids. Also, you may try rectal stimulation to enhance bowel movement. If you can exercise, try mild ones to keep your body toned, after consulting your doctor. In another 2 weeks, you shall reach the stage of fetal maturity and so, do not worry about fecal impaction
and the baby, you can even get an enema
then. Please get further suggestions from your doctor. Good luck.