HCG Levels

Has anyone had low HCG levels through their first trimester and been fine? I have been bleeding for six days but no clots have passed or anything. My HCG only went up 400 in the last 4 days. From 3875 to 4275. I read that it is supposed to be higher than 7,000 by week 7. I will be 7 weeks tomorrow.... trying to be optimistic 😖