has this happened to anyone I'm a bit worried

So I'm about 6 weeks pregnant. I've had spotting ranging from red to light pink to brown only when I wipe for about 8 days now. Ob said that my hgc levels were doubling and my cervixs is closed, but the bleeding was definitely visible. I have some cramping but nothing to severe. My question is had anyone gone through something similar and gone to have a health baby or am I going to miscarry?