My sister has had brown discharge for a few days and passed a clot approximately a week ago, she missed her period and drs told her its because she has a uti. the discharge looks like mine did when i had my 1st miscarriage. any advice?

Bleeding: Brown discharge is usually old blood being cleaned from the uterus. This doesn't mean that she had a miscarriage. Did she take a home pregnancy test when she thought she missed her period?

Vaginal bleeding: Consider blood HCG testing , though if she miscarried it be be low or absent by this time. May also consider ultrasound. Follow up with MD.