A period delay of several weeks like this is usually explained by what you've been through this past month. A severe ear infection, antibiotics, disrupted sleep and stress can all push ovulation later and delay your period. Protected intercourse makes pregnancy unlikely but not impossible, so that's worth ruling out first.
Next Steps
Take a home urine
pregnancy test now, since your period is this late. If it's negative, your cycle will usually return within one to two weeks once your sleep and health settle. Try to get back to a regular sleep schedule, since irregular sleep itself delays periods.
Health Tips
See a gynaecologist if the test is positive. Also see one if your period hasn't returned within two more weeks, for a check and bloodwork.