Help please..

My LMP was 6/26/2019, I ovulated on 7/8-7/9. We did the BD on 7/7, 7/8 and 7/9. I tested positive on a home pregnancy test on 7/20/2019. I went to the doctor yesterday and the first thing he did was an ultrasound and promptly told me he didn’t think I was pregnant and that is was blighted Ovum because he couldn’t see anything. It’s only been 17 days since ovulation and I’m just not sure what to do. He called me back with my HCG and said they are 364 and he said that’s low for 2 weeks... but from everything I’m finding it’s not. Has anyone been here? He didn’t even do a urine pregnancy test. I’m at a loss. I am confused, sad, defeated. Please help.