Your doctor is doing all the routine test associated with ovarian cyst.
Women of any age can and do get
cysts, and
cysts are not uncommon even if your post-menopausal.
Ovarian cysts are 95% benign, so let that be of some relief to you. A Ca-125 can have false positives in pre-menopausal women from conditions like endometriosis and fibroids, ect. For women that are post-menopausal it can be somewhat more accurate, but there are women that have had negative results that have had malignancies.