I got the depo shot for the first time april 20 of this year. Beginning of may I started spotting every day and haven't stopped and it's now the end of may. Usually its just spotting but randomly it's heavy enough for  pad and then it goes back to spotting. I've also been getting dizzy spells and I have fainted twice this month...I took a pregnancy test and it came back negative and all my other vitals are normal. Are these normal side effects of the depo shot?