no gestational sac found

I had an ectopic pregnancy last year and a miscarriage in May. I recently got pregnant and tested positive with home test 4days early.

At 3w 5d - hcg 123 (labcorp)

At 3w 7d - hcg 511 (labcorp)

At 4w 6d - hcg 3588 (labcorp)

At 4w 6d doctor did not see any gestational sac They asked me to come back 3 days later since they think it might have been just early to see anything.

I had worst symptoms in my last two pregnancies but this one has been going good so far. Just saw some spotting after I went for a walk yesterday but it stopped quickly once I took rest.

I still have some hope that it could just be normal pregnancy. But the fact that hcg has been doubling appropriately and it could actually be above 2500 is concerning. I might need to mentally prepare for the worst but my gut feeling says the body hasn’t been seeing any symptoms so far so there could be some hope. Anyone who has similar stories but successful?