Miscarriage

I don’t know if this is the right group or not but i miscarriage at 5 weeks and 4 days. The hospital didn’t know why but my pregnancy hormone level was at a 26 when I went to the hospital. The nurse said there wasn’t anything we could have done. Was it just not fertilized correctly? I’m so confused and I’m looking for answers and it’s tearing me apart. It’s been a week since it happened and I’m wondering why and everything.