vaginal bleeding ?

Hello, I recently found out that I'm pregnant this past Monday ,3 positive urine test . Hcg level showed not pregnant since the results showed level of 4 , I went into the ER yesterday because I started having bleeding , hcg level went up to a 17 (considered pregnant ) and was diagnosed with threatening miscarriage , I have no pain it's just the bleeding , kind of mestrual period . Should I be worried ?