My last period was Jan 5th when I took the test at the hd they said I was about 8 weeks and when I went to the Dr today on march 15th an when they did the u/s I was suppose to be 10 weeks an the Dr couldn't see the heartbeat or anything he was thinking I wasn't that far along. The sac measured 10mm. Does anybody know how far along I could be. I'm quite confused.