TTC contraceptive monitor

Katie🐼 • If at first you don`t conceive... Try, try and try again !
I found on boots that they have a contraceptive monitor that monitors hormones and tells you when it's safe to have sex to reduce risk of pregnancy and when it's not safe.  Has anyone tried it ? Could it be used TTC ? 
I'm assuming if it tells you when it's not safe to have sex if you're TTC you could just use those days to have sex ...