Took pill 2 hours and 30 minutes late

I am on my second pack of birth control. I had unprotected sex this afternoon and my phone alarm did not go off to take my pill. I made sure when I realized I forgot to take it I immediately took my pill for the day even though I was 2 hours and 30 minutes late taking my pill. I take Isibloom. Should I take plan b? Please help a girl out.