Sorry in advance if this is a long post..doctors gave me unclear answers

So on 12/8 I got my BFP

My 1st beta HCG test was 40

On 12/13 I go to ER per OBGYN since I was spotting no cramps or anything.. my levels there were at 84 and they weren’t worried since they doubled.. however they saw NOTHING on ultrasound but figured I was maybe just too early.. my cervix was closed .. I went for repeat beta HCG and my levels dropped to 76.. then 19 and eventually 0 .. Doctors weren’t sure if I had a chemical or a miscarriage or blighted ovum?

I’m just wondering if you had any of this same stuff happen too you? Here I am months later still thinking about this daily and extremely upset..

I am absolutely terrified of this happening again