Hospital visit

Amanda • married. have one baby girl.
So I went to the hospital because I was having light pink discharge and I got worried. They did and ultrasound​ and blood work. He said that it came back 300 HCG lvl in my urine. He didn't run the blood one. He said there was no egg visible on ultrasound. I'm worried I miscarried without knowing it. I see my on on Monday. I should be 4 weeks pregnant. Please help.