Early ultrasound and so worried

I'm what I believe to be 3 weeks since my last period I'm getting a positive test everything I've had lower back pains alot for the past few days so I went for a ultrasound they conducted a transvaginal ultrasound and saw nothing in my uterus, nothing in my tubes but a black circle at my right ovary. Am I still pregnant? Will something show up soon I have another scan at 6 weeks. I thought at least I'd see a sac but my results show nothing like it. Please help I'm so worried. Here are pics of the ultrasound hopefully you all understand and can help me out. Thanks.

First Pic is my ovary second is my uterus