Symptoms but negative tests... help please.

I'm 9 days late. I have taken every test on the market and they are all saying negative. I've taken at least one every single day. My boobs are sore, I'm having some mild cramping, I am nauseous and have a low grade fever. I also am experiencing chills and intense body aches. I've been pregnant before - and I have no recollection of feeling this miserable ever! Thinking maybe it's just the flu and the stress of being a little late made me very late.... is there a high probability I'm still pregnant? Also. 2 days after my missed period I have some cervical mucous which looked a lot like the cm when I'm ovulating... but there is no way to be sure. Thoughts? I'm over here stressing about ectopic pregnancies and whether I can take medicine for the flu... or if I shouldn't because I'm probably pregnant...