I'm so confused! Need advice about threatening miscarriages

Tasha
So after my husband and I had sex I started bleeding didn't think nothing of it cause a lot of people say it's normal. But the bleeding was more than spotting.. I go to the ER and long story short they said my cervix was closed and it wasn't that much blood.. They didn't have an answer for me! So they just said I'm threating to have a miscarriage! They said to check in with my doctor and take another blood test within 48 hours and if my hcg levels go down then I lost the baby.. I'm just so nervous cause this will be my 3rd miscarriage 😢