Low HcG levels ?? What to do?

On Friday and Saturday i took a total of 6 preganancy tests , all coming out positive . now , im not really sure of the date of my last period , but they estimated 4 - 5 wks preqnant . i did the bloodwork and my HcG level was 80 . the doctor said that was low and explained to me that many women miscarry with low HcG levels , im stressing it alot and in 2 days im qoinq to take another bloodtest . Has anyone had low HcG levels resulting in healthy , normal pregnancy . or any advice . .