I last started bleeding on 24th aug and have a 30-32 day cycle. I am very late for my period but getting negative pg test results. Had a line appear then disappear (very faint) so bought a clear blue digital and it said not pregnant. Could I be pregnant and it not be showing up? Also I took levonelle on the 18th aug, before I had my last period. Can you shed any light on what might be happening here?