I had unprotected sex about a week and a half ago for the first time ever. i think i'm on my period but paranoid. my blood is darker than usual.

Take a test: If you have your period it is unlikely that you are pregnant but take a test so you can stop,worrying. It sounds more like you are fearing the consequences of unprotected sex. If you make that a habit, pregnancy is a possible outcome. Consider yourself lucky and just learn from this experience. If unattached, carry condoms with you . I hope it all works out.