Long post possible miscarriage

Based on my LMP I’m expected to be 7w2d. Started bleeding lightly 2 weeks ago which led me to going to the ER when I was supposedly 5 weeks along. They couldn’t see a gestational sac on the transvaginal ultrasound and my HCG levels were 133. They suspected a threatened miscarriage and advised me to schedule an appointment with an OB to get blood work (HCG)done 48 hours later. So I did that, HCG rose to 313 but bleeding continued(very lightly still) so they advised me to go get HCG another 2 days later and at that point it was 551. Fast forward to this previous Tuesday and levels have risen to 2062. Today I had an ultrasound to which they have now found a gestational sac but nothing else. Also, based off their scan, I’m dating to be 5w2d instead of 7w2d which is what I would be based off LMP which was Jan 7. Spoke with the DR after ultrasound and she said she doesn’t want to call it a miscarriage because she’s thinking I’m just dating earlier or ovulated later than i thought. She advising me to come back next Friday for yet another ultrasound and I just got my blood drawn to see if HCG is still rising. Has this ever happened to anyone and still had a healthy pregnancy? I’m assuming miscarriage tho