BFN 16 days late

My cycle is usually 27-29 days. I’m on day 45 right now. I feel nothing, I don’t feel pregnant. I don’t feel like I’m getting my period, my doctor says there is nothing wrong with me. They won’t do a blood test until I’ve missed 2 period though. I don’t know why that’s just what they said. Anyways I took a test Friday and it was negative, how long should I wait before testing again? Or should I just wait until my doctor will do the blood test?