IVF transfer day 3

Doing my first <a href="https://glowing.com/glow-fertility-program">IVF</a> now. We retrieved 10 eggs, 5 matured but only 1 fertilized. 
So we transferred 1 embryo yesterday on day 3 (cell 7). A little disappointed we only had 1 good embryo to transfer but just want to know if there are any success stories with 1 embryo transfer on day 3?
Thanks!! =)