Am I pregnant?

Hello everyone, my husband and I have been trying for 3 months now to conceive our first child, I am now 20 days late on my period and I still am getting negative tests, the only symptoms I have are fatigue, nausea, and dizziness. I am wondering how much longer I should wait for blood work to confirm or not confirm that I am pregnant or not and if this sort of thing has happened to anyone else and how long it took before they showed a positive pregnancy test.