Vaginal bleeding/discharge

hey there,
i'm a 22 yr old stay at home mom of 3 kids, i had my tubes tied after the last baby. about the time i was supposed to get my perios, i started having alot of brownish discharge-like dried blood, that went on for about a week, it wasn't enough for a tampon or anything. the second week, it was alternating between brown and red, but still not enough for a tampon. i havent been having any abdominal pain or anything like that. i have had 2 ovarian cysts before. i'm just kinda freaked out. i've had all normal pap smears,and std tests. has anyone had anything similar?. i would really appreciate some help