Pregnancy

I got pregnant some time in october had a miscarriage the 26of october right after the miscarriage I had sex in between the miscarriage I.didnt have a.period.my last period was sep 19 I was told I was pregnant I took 5 home test one in the morning one in.the evening ine at night and two the next day came back positive however I am concerned because mu hcg levels are slowly dropping and the doctor say a possible miscarriage but im not spottin or anything could it be possible that my hcg.l levels didn't have time to go back down since I got pregnant right after. When I did a transvaginal ultrasound she couldn't see anything but she said everything is ok I.go back jan 8 I'm nervous because I never been pregnant besides thst miscarriage and afraid I might have another one