Can Depo Injection Cause Pregnancy Like Symptoms?

Hello docs, i'm 19 years old and i recently had a depo injection on dec 13th. the first day of my last period was nov 27. i completely missed my period for the entire month of dec. i had unprotected sex a few days before the injection (which is when i suspect i conceived). i also had not received the injection within the first five days of my last period. now i am hungry all the time, tired during the day, i have tender breasts, occasional cramps and headaches, sometimes nausea and extremely sensitive to smell. i took a hcg test and it was negative, but i know my body and have been pregnant before. i heard of a woman who got pregnant on depo didn't have positive hcg until she was four months. can this just be the depo affecting the results of a false negative test? can getting pregnant before depo harm the baby? can getting the shot more than five days after a period affect the success of this birth control method?