Blighted ovum or too early?

Hello guys, so my LMP: October. 3, I have PCOS. I took a pregnancy test on Nov.6 that was negative and on Nov 13. with morning urine that was negative. I got my first positive pregnancy test on 11/16 with evening urine. Yesterday I went to my OB and the ultrasound showed a gestational sac but no baby. First of all the ultrasound quality wasn’t that great (he has 2 offices, I went to the office with the worse ultrasound because I needed to see someone and he was there). Also my PCOS makes my periods really weird so my ovulation dates are always way off. If I ovulated like someone with a normal 28 day cycle I should be 6 weeks 6 days. But the dr said with PCOS he is predicting me to be at the end of my 4th week. He wants me to repeat ultrasound in 2 weeks. He said by that time we should be able to see baby and a heartbeat. IDK how i’m going to survive guys. I’m a mess and afraid for blighted ovum. The dr does not seem worried at all. IDK why i’m dying over here. Anything similar happen to anyone else?