Bump on my ovary inside. grew over past 5 years. doc says it's a cyst. i was worried of cancer. should i get another opinion?

It depends on size: Small cysts in the ovary are quite common. If the size is larger than 1-2 inches, then it is a good idea to get a second opinion because you want to be sure that it is not the beginning of Ovarian cancer which frequently presents as a growing cystic tumor . A short term follow with an Ultrasound examination in 3 to 6 months is another option to check it for further growth.