What Causes A Missed Period With Low HCG Levels?

hello i got married on dec 2009, previously my cycle is for around 45 -50 days and last for 3-4 days... and for the month of april, may & june it was 30 days cycle... my last period was on 15th june.... and all my upt test went negative.... today i took blood HCG test and the observation value in Less than 1...

what is happening.. am i pregnent?????