PREGNANCY OF UNKNOWN ANATOMIC LOCATION

Soooooo I’ve been back && forward in the hospital since Sunday my HCG levels are rising but they don’t see anything in my uterus. I’ve been diagnosed with a spontaneous abortion (with rising hcg levels) , ectopic pregnancy (then asked if twins run in my family), then told they’re not a 100% sure if it’s ectopic. Smh, I’m a first time mom I’m so confused && scared && don’t understand this. My HCG levels were 4235 Tuesday. Could it be too early for them to see anything or maybe there is a problem they just can’t determine it yet?