Dettol is not a reliable way to test for pregnancy. As it is usually an important test for most people, the best thing to do is either visit your doctor and have them perform a pregnancy test, or go to your local pharmacy and pick up any over-the-counter (HCG) pregnancy test. Most of them are very easy to use and have a clear indicator of whether or not you are pregnant. These can sometimes show a false positive or negative, but are far more reliable than the Dettol Pregnancy "Test".
You should know one thing that there is no reliability of dettol test because it can not detect hCG in urine. Dettol will turn milk like when you add water or urine regardless of pregnancy. Take only hCG pregnancy test.