The main reason why the blood is brown on the last two days of your period is because the amount of vaginal bleeding on the last two days is relatively small. Sometimes, after the decomposition of vaginal bacteria, what comes out at the end is brown or rusty or even dark coffee-like blood, so you can rest assured. However, it is important to rule out the possibility of other causes of brown vaginal bleeding: the first is the possibility of ectopic pregnancy. Even if the vaginal bleeding occurs on a day when you should normally have your period, it may not necessarily be a real period and you need to rule out the possibility of ectopic pregnancy. The second is to rule out the possibility of menstrual disorders, such as prolonged periods or dripping vaginal bleeding, which are endocrine causes of menstrual bleeding. The third, exclude diseases of the cervix.