Give me your opinion

I was pregnant back in February and ended up having a blighted ovum and misscarried on the 6th of March and continued bleeding until the 12 after that I didn’t get my period and took a pregnancy test on the 12th of April and it was positive had my hcg levels tested on April 19th and April 22nd and they doubled from 5100 to 10200. The. Went to my doctor on may 3rd and he is telling me I am 4 weeks along? I think I am further along based on when I tested positive and my hcg levels. I don’t go back to see him until June 7th.