Confused ?

The app says I ovulated November 24th ( aware it can be inaccurate) I had unprotected sex the 27th & 28th took a plan b the 31st tomorrow menstruation will be late by 2 days (aware could be side affects) I took a pregnancy test to be safe and it was negative. In my lifetime this is my third time taking a plan b and usually even when late I still spot…. I haven’t yet. What do you recommend ? How long should I wait until testing again? Thoughts ? Advice ?