We lost the baby

Yesterday at 6am I woke up to cramps and bright red blood. I was 5 weeks 2 days yesterday. I went to the hospital and the doctor did an vaginal ultrasound and said it looked like something was definitely in there (my uterus). But she did a blood draw and said I was negative gor pregnancy. That was it. No better explaination. Just "you miscarried, you can try again as soon as you want". Id love to know what the hell she saw in my uterus. But I'm too heartbroken at this point to bother. The baby...our second baby who we were so excited for...is gone. We were picking out names. We were so happy...now...I dont know....I feel lost.