Question has anyone e experienced this

I had my last period March 13 to 16. I (as per the app) I should have ovulated 26 27 28 29. My husband and I had sex 26 & 29th I tested a positive test on my 1st day of my missed expected period. The app says I am 6 week 2 days and I had an appointment today with the OB. He said my cervix is closed but the ultrasound showed no baby in the clear spot and bleeding in the uterus, he said either I am not 6w2d and I am off by 2w or I am miscarrying. so they did bloodwork yo check hormone levels and a ton of other things. but I know I always check the periods and sex on the application....any thoughts? early or miscarrying??