Girls, could you please tell me what happened today at my ultrasound? …

Girls, could you please tell me what happened today at my ultrasound? I went for another one and it showed nothing but something there that was 3-4 mm, but like last time, my last period was in December of 2016, my hCG level was 103 last week, now they said to repeat the test and then go for another ultrasound next week. Is this even possible? But the test shows two lines, according to my calendar I'm already 6-7 weeks pregnant.