1 out of 2 embryos transferred

Sa
Hi everyone,
I had 2 embryos transferred 12 days ago and I found out yesterday I'm pregnant 🤰🏼💝 yaaaayyyyy !!!  I was wondering though, what happens with the 1 out of 2 embryos that didn't make it ? Does he just fall out or something ? Will I be having some kind of spotting or period ? Thanks for your insights ! Keeping our fingers crossed this baby hangs on tight 🙏