Hi, Precy, when a doctor tells someone she is a certain number of weeks pregnant, he is not saying that number of weeks ago is the day she conceived. The "weeks" count in pregnancy, as counted by doctors, begins earlier, on the first day of the woman's last period, not from the day she actually got pregnant. Conception is unseen and hidden, but the first day of the last period is obvious and clear. So (in the days before ultrasounds), that was when the medical profession began the convention of counting pregnancy from the first day of bleeding of the woman's last period before she got pregnant and they stopped coming. This means, if a doctor says "You're 7 weeks 2 days," it means she is 5 weeks 2 days from conception. Sounds like she got pregnant on around the 20th of June.
Even in the days of ultrasounds, that older counting method is still used by doctors. That is why pregnancy, that takes 266 days from conception to full term, is counted as 280 days (40 weeks) long -- they add two weeks at the front end to move the start of the weeks count back to the (computed) first day of the last period.
Thank you so much for your response it is much appreciated