Overall, in your 30s you have about a 15 percent chance of getting pregnant in any single ovulation cycle.

http://www.babycenter.com/0_age-and-fertility-getting-pregnant-in-your-30s_1494695.bc

Overall, in your 30s you have about a 15 percent chance of getting pregnant in any single ovulation cycle, according to leading fertility specialist Sherman Silber, director of the Infertility Center of St. Louis at St. Luke's Hospital in Missouri and author of four best-selling fertility books, including How to Get Pregnant.