No period , 4 days late

This is the first time I've ever been late besides when I was pregnant with my son. I am on a 32 day cycle and it has been like clock work since I have gotten off my nexplanon implant . So I'm not sure why my period has not came on . It was due on the 21st this month and nothing I haven't had any spotting or bleeding . Just cramps . The day after it was due I got a horrible sore throat headaches and body ache and it literally felt like I had the flu now I am doing a lot better. Friday at work I got sick and had to leave early that day I took a test at a clinic and it was negative and I wasn't sure why so I went to my doctor and got blood work done. I am still waiting on results . But I normally have a regular period every month I am not sure why I am late and getting negative test . Can someone help me understand why or am I testing too early ?