Period help

So I recently took Plan B on the 9th, bled on the 13th, and still spotting. I am due my "normal" period according to eve, to how it was on my b/c, today. However I ran out of my last b/c almost a month ago (hence the plan b). Has anyone taken plan b and known when you'd have your normal period or will this be considered my "normal" flow and I have to wait another month for my body to have a period? I am wanting to get a new b/c method started but was told that I can't start until I am on my period