A hCG under 0.1 this many days after intercourse effectively rules out an ongoing pregnancy for you. Implantation and a rise in hCG normally happen well within this window. If you had conceived, the test would usually have shown at least a faint positive at some point, not stayed flat negative throughout.
Next Steps
An extremely early pregnancy loss, sometimes called a biochemical pregnancy, can happen without ever showing a clear positive test. That's different from a true missed pregnancy, which needs a scan to confirm.
Health Tips
If your period hasn't returned on its own by now, please see a gynaecologist, since a delay this long is worth checking in person rather than guessing from a test alone.