Are you saying they gave you some medication to soften the cervix? Sometimes this is done so they can get a sample of the uterine lining for a biopsy.
I would not get too worried about the bleeding. It is actually fairly common to have some post-menopausal bleeding especially in the first 5 years after menopause. The reason is that the ovaries never really shut down and during those first 5 years or so after menopause, you have some surges of hormones than can trigger bleeding. MOST cases are nothing serious although they do say any episode of post-menopausal bleeding should be investigated.
Also, vaginal atrophy from the loss of estrogen can cause some irritation and bleeding. It also makes you more prone to urogenital and vaginal infections which may explain the discharge.
Let us know what you find out. And try to remain calm since it is unlikely to be anything serious.