Pregnant? Hcg test

Okay, so long story short I bled twice in August once 14-20 then bled again 29-31. I had a yeast infection and it cancelled out birth control so I took plan b on the 24 so the 3 days of bleeding is considered a period according to obgyn. So that puts me at about 3 weeks 6 days. I got my first positive at 3 weeks. I went to the er for pain and dizziness and they said my hcg yesterday was 400. My question is. Is that normal for 3 weeks 5 days?