Today was my 3rd day of injections. I've ran test-p twice before and this is my first time with sustanon. For about 3 or so days after an injection, my body has the same feeling as if I had a fever, but I don't. I feel as if my body may be fighting off the injection. A friend of mine told me this was normal and I should give it time.. Is this true or should I be more concerned? Very legit source.