My tickers are measuring according to my LMP (April 28th), but I have a very good idea when I conceived as we were limited in the department (either May 9 or 10, unless those swimmers stuck around longer). On my "What to Expect" app. for my iPhone, I plugged in the conception dates to see what would happen differently, and it put me up to 3 days further along, with an EDD at the end of January! Which is more likely? Should I just stick to the LMP until I get a scan telling me otherwise?