PLS HELP- 2 weeks late


today my period is 13 days late. I took 2 tests a few days apart, both negative. I have had unprotected sex, he pulls out usually. I am on the pill and rarely miss. I'm not stressed and nothing in my life has changed. the only thing I've done differently is about 2 weeks ago on the day I should've gotten my period I smoked for the first time (dab pen if it matters) and I have been every few days since then. any ideas as to why it's late?