TVS result ,NO SAC found :( 6weeks

Sabi ng OB ko 6 weeks preggy ako this day august 18. So ayon, sb nya mag pa TVS scan ndw ako. And then kanina ang result ay walang makitang Sac or baby.i was so dissapointed. But then , sbi ng doc it's either wala laman or too early ang pregnancy at bka nagkamali lng dw sya bilang. And I felt so mcj stress awhle ago. And then ang gnwa ko, nag pa qualutative serum pregnancy test ako ung sa dugo . And fortunately positive ang result. Ask ko sna mga momshies , may ngyyre bang ganitong incident sainyo.. Very confused n tuloi ako dhl sa reault ng TVS scan na yan.. Last mens ko was july 7 . Sbi nla it's either late ak nag ovulate , maag masyado prengnancy kaya d madetect sa vaginal scan or d dw tlga ako pregnant. Pero bkt postve nmn ako sa result ng serum blood test PT ? Also i already have 4 urine PT and it was postve too.#firstbaby