Period hasn't started, had protected sex, used careful precaution. why is it late? thanks!

Period: Have you checked that you are indeed not pregnant? If you have, and are not pregnant, then we can have periods that are irregular and late at times for one reason or another - stress, hormonal fluctuations, weight changes. See what the next month brings and then take it from there.

Can't tell from here: ...but a home pregnancy test at his time may allay some of your concern.