Your blood test under 0.1 and four negative urine tests, the latest three days ago, make pregnancy extremely unlikely right now. The emergency pill you took can delay your period by days to a few weeks because it disrupts your normal hormone cycle for that month. This is a common and expected effect, not a sign anything is wrong.
Next Steps
If your period hasn't started within another one to two weeks, repeat a urine test and see your gynaecologist for a pelvic ultrasound to check the delay.
Health Tips
Come in sooner if you get pelvic pain, unusual bleeding, or spotting, since those need to be checked directly.