Pregnant or not?

I am taking birth control pills because my husband leave for three months. Now that it's his last week and supposedly, on October 5 I'll be having my monthly period. But yesterday, I got my period earlier and its very few that can't even fill a panty liner and stopped today. Now I am wondering if it's a period already or am I pregnant? Is it possible even if I'm taking pills po? Thank you so much to anyone who could explain. ??