My first u/s was on the 7th week and we were able to hear the heartbeats. From what i have heard for x reason you might not be able to heard it the first time and still be ok
In other words, when I said "is at about 5 weeks and a day or thereabouts," I meant in your fifth week of pregnancy, counted the medical way.
It is said to start beating around 22 days after conception, which (given the way pregnancy is counted from the first day of your last menstrual period) is at about 5 weeks and a day or thereabouts. However, if your last period was irregular or your ovulation was a little early or a little late, that time frame is not entirely precise.