Late period, but not pregnant. Plan B messed me up?

Ok so in late October I had my period, then I took plan B and got my period again after a week, so that was two periods a week and half-ish apart. Since then I’ve had protected sex, the condom didn’t break, everything was fine, but I should have my period and now it’s late by 3 days. How much does plan B mess with the cycle? I haven’t taken a test but I know I’m not pregnant. My regular cycle is like on the 23-29 ish of every month, so will it go back to regular or will it be jumbled up?