6weeks pregnancy. How can we confirm?

My LMP is 27-Sep-2019. Beta hcg level as of today(6 weeks) is 35809mIU/ml. And USG report says 'Gravid uterus of 6 weeks' and 'hemorrhagic cyst 3.9x2.5 in left ovary', and CRL 3mm with good FHR. However the doctor said the hcg level is too high and this could be a heterotopic pregnancy. When asked about FHR also, she doubtfully said let's wait for one more week (though the report said good FHR). I don't have any health issues. No nausea or fatigue, but there is moderate pain in abdomen sometimes. but there is no spotting and the pain is also not particular to one side of pelvis. Sometimes it pains near navel and sometimes on either side of pelvis. And the pain subsides by itself in few hours. I'm now worried because of the doctor's doubtful answers, if this could be a heterotopic pregnancy or if everything is fine. How can we confirm?