Advice please

Rebecca

Hi everyone I went for my first ultrasound today my GP dated me at 7 weeks going my last period but ultrasound showed I was only measuring at 5 weeks, could see yolk sac but no heartbeat at this point as he said it was too early, does this mean I ovulated late? Also had slight spotting when I wipe for the last 2 days, still got a strong positive on a hot yesterday....