I'm 6 weeks 6days pregnant, my last period was affected by plan b before it started, but i had it october 13, had intercourse the 27th, could i have ovulated then and become pregnant by the 27th?

That's possible: Those dates sound possible. If 7 weeks pregnant now, the estimated time for ovulation and conception would be 5 weeks before now. (IF one has sex with more than one guy, the key is to space the guys at least several weeks apart. That way, it doesn't matter exactly when conception happens... one can do the math to see who the father of the baby is.)