ai have been having the depo shot 3 times now and im due again soon, the  first time i bleed practicly for 3 months with a few days break before having a tablet to stop it. i got told the pregnancy symptoms stops around ur second shots but recently they seem to be worse, my emotions are everywhere, im constantly tired, i have back pain, stomach pain, been sick and really spoty along with gaining weight even though iv been on a diet. 

could i be pregnant iv done a test but it says negative even though it was just a cheap thing ?