My wife had last period on 5th May. After that till 23 we did not have any contact. She missed period in June and on 9th June pregnancy test was negative. Then we did test on 15th and it came positive. We had first scan on 22nd June and no heartbeat found. After we had it again today 2nd July and still no cardiac activity found. As per the scan it has completed 6 weeks and 3 days. We have been advised next scan after 1 week. We are confused whether there is any issue with baby or there is incorrect calculation of weeks. Could you please advise?