4 weeks and 4days preganancy . Ultrasound and TVS

I tested at home 3 times and results are positive. Yesterday we went to see doctor and I was undergo ultrasound and doctor couldnt find anything . Then I had TVS ultrasound and got same answer . Doctor took my blood sample for HCG test. I know patience is the key but we are so worry as this is our first child. Can anyone help to share your experiences? Thank you so much.