Help me with this please

Baby

So way back in July or August I had sex unprotected, he didn’t cum in me he pulled out. I had my period August and September and now I’m on my period this month, October. My periods is the same as they were before. But lately my friend said some girls can be pregnant and have their periods, but when I search things up it says it’s impossible for girls to be pregnant and have (periods) they can bleed tho but it’s light and short. Like I said before my period are they way it was before. 5 days and heavy and you know cramps. But since my friend said this it got in my head making me think “what if I am pregnant” my period are no where near light and short I just don’t know