15 weeks with a dark brown discharge

Hi ladies. Need some advice please... iv been having a dark brown discharge along with left abdominal cramping. I can feel it come out even if I'm sitting.  've been hospitalized twice already for bleeding. My GP put my on bed rest hoping the discharge would subside however I noticed this morning that there isn't any change. I'm afraid to be admitted again as it would be the third time this month. Anyone else experience this? Is it normal and all part of pregnancy?