5w6d a week behind?

India • 👼🏽 👦🏽 👼🏽 👼🏽 👼🏽 🤰🏽

Had an early scan just to check on things, and saw yolk sac, baby + heard heartbeat of 121!! I thought I was a week ahead (6w6d) but baby measured a week off. Maybe I ovulated late?? The last day I had sex was 07/03/19.. hoping i just ovulated late & baby didn’t stop growing sometime last week.. has this happened to you? I’ve had 3 miscarriages in the past.