hello every1 plz help...i am totally confused....my last normal period was on fed 6 2013

my periods are regular and 28 days +/- 1 day..... my periods were late in march ..it was on 13th....bleeding was scanty..usually my periods last for 4 days...ths time only 1 and half day...tht too wen ever i went to washroom.. thn aftr 2 days brown spotting for 1 day.... thts it.. my home pregnancy test were negative and my blood work was done on 19th it showed HCG 6.8.... now i hv most of the the pregnancy symptoms viz bloating, frequent urination, hungry a lot , headache, rib pain at nite, breast sore sumtimes....my doc say i am not pregnant as my period is not cleared i am suffering ths...wat do u ppl thnk ...am i pregnant?