Doctor didn’t acknowledge chemical pregnancy?!!??

Hello ladies, so a little back story. I had a miscarriage last month on 2/20, bled for a week after & my HCG levels were officially 0 as of last week, 3/13.. however this Monday I got a positive on a hpt, went in Wednesday for blood work which showed an HCG of 10.. I understand it’s low but my doctor said its enough to be positive. Fast forward today, I had some heavy bleeding. I went into the ER & they just said it was possible I wasn’t pregnant at all & the bleeding I’m experiencing is AF??!? Does anyone have any experience with this? Initially I thought I had a chemical pregnancy, but now I’m confused. Is it normal for hcg levels to fluctuate like this