I am 16 weeks pregnant with my third child. at 13 weeks i discovered a gush of bright red blood twice in one d?

ay. when i went into the hospital the doctors told me nothing too much but they seen a heartbeat and movement of the baby. they wanted me tto come in for a hcg check or something in that sort, but i never went but since that day i have been bleeding dark brown blood on and off daily, i notice more in the mornings. could my baby be dead inside of me or am i miscarrying?