Hi - yes, it CAN work on the 1st try! I was successful with the transfer of a single 5 day blast! No issues except for age, and good lining. Make sure to get sufficient progesterone support. I did crinone b/c I couldn't do the shots, but the shots are what most do. Crinone is much, much more expensive (like $1k+ for the 8+ weeks I was on it).