Who is really 2 weeks

missa7997

I am trying to find info on what is really happening in belly.  The problem is all the websites are saying that they start counting at the first day of your last cycle.  I was ttc for while and know the exact date we "conceived".  We found out (at the dr.) when I was about 10 days that we were successful.  I will be just shy of 5 weeks when we hear the heartbeat.  This being my first I am dying to find any information I can for the size to what is really happening in there.  Can anyone help?