Threatened misscarriage 😔

So I did two pregnancy tests yesterday both with faint lines.. I was super exited but last night couldn’t sleep had a lot of backache.. today morning I started bleeding A LOT and horrible cramps! Worst cramps ever!! went to ER they made me blood test and said my hormone level is at 12 wich either means I am a few days pregnant or I’m loosing the baby... they sent me home and I’m supposed to make another test in two days.. I’m just trying to rest and I took a digital test just bc I had it there and said pregnant... did somebody have this in their pregnancy??? What did you do to save your bby??? Please I need help!! 😭😭😭😭💔💔💔💔💔💔💔