Nervous

I went to the e.r 3 days ago due to spotting(dark brown). I was told baby was measuring at around 6 weeks & something days but said my blood levels were fine.. yesterday I went to the obgyn & was told the baby was measuring a bit smaller than what I was told at the e.r. I was sent to get my blood drown & won’t know if it’s a miscarriage or if I got pregnant later than what I thought.. I am still spotting(dark brown) but I haven’t really had any bad cramps.. Has this happened to anyone & still had a healthy pregnancy?