Brown "period" blood, please help!?

my period is usually very consistent, but this month it was a week late, hen when i started "my period" it was a thick brown type of blood, which ive never had before. i have never been pregnant nor do i have any symptoms, except maybe some cramping that doesn't last long, and my boobs are only sore when i push on them. though i do have unprotected sex daily, because i am trying to conceive. could all of this be a sign of pregnancy? please help!