I'm Pregnant Possible 4-5 Weeks. I Had A Gush Of

I'm pregnant possible 4-5 weeks. I had a gush of blood on Saturday morning, went to the ER on Saturday and they said my cervix is closed, good sign but my HCG level dropped from 158 to 82. No cramping, not bleeding anymore, never soaked a pad, just that gush of blood and bright red when I wipe yesterday. No more bright red just brown old blood when I wipe. I have my OB/GYN appointment on Thursday. I'm having major heartburn, I vomit after lunch and easily disgusted. Very thirsty and breast tender. Any possibility that HCG level was wrong? Would these be signs of miscarriage?