I Have Had Severe Bleeding And Pains Similar To Childbirth

I have had severe bleeding and pains similar to childbirth went to hospital my HCG level was 2,700 on Thursday on Saturday they was 1,700 n a positive pregnancy dip test this was a shock as I have a 7 month old baby I have a scan booked and my belly swollen hard and sore I'm so confused to if I have definetley list the baby or if I need medication for infection I don't understand