I saw my period this morning,it's a day late.had constipation yesterday.saw light blood stains while wiping three different times.I am sexually active without protection,the period is light and pinkish in colour.what is wrong?

You're either starting your period a day late (very common), or you are pregnant (also common with unprotected sex).

Take a home test to be sure.

I agree, you should be able to take one now that you are at your period marker. Take it in the morning with your first urine of the day for the best result.

It could be that you are just late this time round, but take a test preferably first thing in the morning.