Randy, 2dt, 3dt etc mean the no. of days the embryos are cutilvated in the lab before transfer usually term it 2days transferred, 3 days transferred etc. If the embroys reaches 5 days it is called blastocyst. In cases where the no. of embryos are less the Dr unlikely will cultivate till blastocyst as the survivor rate is higher in mother's womb than in the lab.
In worst case, the embryos may not grow further after a certain time so Dr usually advise to do ET on day2.
Not to worries too much, at least your eggs are matured...look forward to be united with your embbies! Gd luck n best wishes!