Took Plan B, menstruating, pregnant?

I had unprotected sex right after my period early Aug, took plan B right after, menstruated first a week after that, then around end of Aug to early Sept, again around late Sept, had protected sex that time on period and am having my period again now late Oct. menstruation has been generally heavy. And I didn't have sex apart from the mentioned times.

I'm not supposed to be thinking about pregnancy, but I am not at ease. I'm on my 6th day, ending already and it's just that it's brown like spotting. But seriously, my menstruation has been really heavy since i took the pill once.

Are there chances that a person is pregnant though on period? I'm sure I don't have any symptoms, but isn't it too early, like just a month in, to be thinking of symptoms. It was just i was looking around and there are a lot of women writing that they were still menstruating months into their pregnancy. I'm hoping mine is the result of the morning after pill