Help please

I’m 6week 3 days past the first day of last period, last week my boob was super sore and now they’ve not been sore for about a week and I have no symptoms at all apart from the odd cramp but nothing major.. soo I went of an early ultrasound last night and I’m measuring at 5weeks.. soo worried that the sore boobs have disappeared too and I know I should be 6w3d because we only bd once on ovulation day, I track my ovulation and my periods are always spot on....