SOS plan b help needed

condom broke on sunday. not on birth control. boyfriend got me plan b (we live in canada, it's a levonorgestrel pill) and i took it about an hour after the incident. my period was due on monday (as in the day after the incident), so now it's four days late. ive been experiencing some cravings, thick white discharge, headaches, fatigue, and mood swings. getting really worried that my period still hasn't come and that i could be pregnant. should i be worried though?