Need some help and very confused

Tiffani
I'm so confused, took a home pregnancy test on Friday came out positive, went to the ER Saturday with some spotting, the doctor took my HCG levels and came back as 8 and then did a vaginal ultrasound and said it was too early to see anything, went to the ER on Sunday for a little heavier bleeding nothing super crazy and some mild mild cramping and doctor said sounds like an early miscarriage but wasn't a 100% sure to come back Monday and retest my HCG the level came back as 4 but the doctor said becuase it was a different lab and due to margin error they cannot tell me a 100% if it's truly a miscarriage or very early on in pregnancy and to follow up with my doctor or OB in one week, has anyone had anything similar or know of levels increasing then decreasing and then going up ? I'm so confused and this is mine and my husbands first pregnancy and I just want everything to be okay