Its never safe to try to induce labor on your own . Baby will come when he/she is ready. I had alot of preterm labor with my first two. We were able to keep my daughter in until 37 weeks and she did OK but my son was born at 36 weeks 2 days and he had breathing and feeding issues. As uncomfortable as pregnancy is during the third trimester its best for baby to stay in as long as possible.
37 weeks is considered full term..but I would always ask your doctor 1st