Plan b

So I read somewhere that plan b delays ovulation. My question is I already got an LH surge and I believe ovulation. I am 3-4 days away from my period and still no symptoms that it will be coming anytime soon. I also read that a plan b delays a period because it delays ovulation. Do you think I could be pregnant or do I not have any symptoms of my period because of the plan b? Also anyone who has taken plan b did it delay your period or no?