My periods were supposed to start five days ago but i amgetting a light flow of a dark reddish brown. i had a lot ofunprotected sex. is this my period or can i be pregnant?

Do a pregnancy test: Most of the time there is no bleeding when one is pregnant, but not always. Since you have had "a lot" of unprotected sex, there's a good chance you are pregnant and are having what is known as "implantation bleeding". Since your period was supposed to start 5 days ago, if you are pregnant, the test should be positive by now. Do a test and see a doctor if you are pregnant.

Maybe pregnant: If you aren't using protection you should check a pregnancy test.

Possible pregnancy: To dismay your concerns, you should do a pregnancy test. This will answer your question.