Am Six Weeks Pregnant, At First The Doctors Thought It

am six weeks pregnant, at first the doctors thought it might been an ectopic but later ruled that out after my HCG kept raising but not to the satisfaction of the doctor, it was 1152 by the fifth week. My worry is that the doctor said he cannot see the baby in the womb even after the viginal scan.
I have been asked to do another scan on wednesday.
Do i need to worry? Please give me your professional advice