found out about 2 weeks ago that i was pregnant through a couple of at home pregnancy tests. i went to the doctor and had blood work and urine tests done, but both came back negative for pregnancy. the day after i went to the doctor i took another at home test and it was still positive and yesterday evening i started what seems to be a period. it started out dark brown and since then has become more red and has clots every once in awhile. went to the doctor today to see what could be wrong and they said this time that my tests came back positive for pregnancy but my HCG levels were low (320). should i be worried about a miscarriage or no?