1 blastocyst?

JEN • Married 12/31/11 TTC since 1/1/12. We suffered a mc 12/23/14 :( started 2015 we did injections, still BFN, did 1 IUI BFN finally moved to IVF (long lupron protcol) in Sept. BFP! EDD 07/17/16
Hi ladies, my dr called me today to change my transfer option. She said the team of Drs met today and decided that I should only transfer 1 I stead of 2 due to the chance of twins and my heart. we were gonna do 2 3 day but now we are going 1 5day. Has anyone had success with just 1 blastocyst being transfered?