Thanks for consulting at my virtual clinic. I have carefully worked through your case, and I can realize your health worries. Being your physician, I assure you not to worry as I will take care all of your medical concerns. Diane 35 and Metformin XR will not cause increase chance of pregnancy on having unprotected intercourse. since you are having PCOS the chance of becoming pregnant is lesser than a normal women. It is always better to have protected sex ( condoms) for lots of other reasons other than pregnancy it prevents transmission of sexually transmitted diseases. continue taking your medication regularly, maintain a proper diet rich in green leafy vegetables and fruits. reduce junk foods, oily food and carbonated drinks as they will increase your weight. go for regular aerobic exercise and physical work outs. be physically active involve yourself in swimming and sports. Hope it helps. If you need further, detailed and quick assistance related to any health issues in future, feel free to ask me a question directly from my profile. Have a wonderful time ahead. Best Regards! Dr. Arunmozhi varman