Missed period

I am officially 2 weeks late... I have taken 2 pregnancy tests 4 & 2 days before my period was due.. both were negative. I am planning on testing again today. I have food aversions, nausea, & indigestion/heartburn. I am extremely tired... I have been off of Depo shot since February 2017... (that was my last dose, so it should've been out of my system by April/May 2017) I have been TTC with no luck. Could this be?? I am almost 24. My last pregnancy (2nd trimester loss March 2016 was due August 2016) I didn't know I was pregnant until I was about 6 weeks. Help??!