Evening primrose oil???

I had a check at 33 weeks due to strong Braxton hicks. The doctor said my cervical is already soft, but didn't seemed concerned because this is my 5th pregnancy. My question is at 36 weeks would it be safe to go a head and start evening primrose oil or red raspberry leaf tea? I AM NOT TRYING TO BRING ON LABOR. Only help with a smoother labor. I plan on asking my doctor at the next appointment.