Since there's been no penetrative contact, pregnancy isn't the likely explanation for this delay, even though it's natural to worry.
Next Steps
Stress, weight changes, and even a viral illness can push a cycle off track, so please see a gynaecologist to check for these along with your fever-like feeling and dizziness.
Health Tips
If the delay crosses a few more weeks or the tiredness and mood swings get worse, please don't wait it out on your own.