CT scan for cyst

So I was told I have a 4cm complex cyst on my ovary discovered via ultrasound at my new dr. Previous ultra sound results show it’s been there since 2017 and have grown about 3 times since. CA125 results came back negative (level 10) but today they called to say my gyno wants me to have a CT scan. And when I google ct scan ovarian cyst everything says cancer. Is it normal to have. CT scan after an ultrasound? I just don’t know if I should be more concerned than they’re leading on. 😔