i dont remember

i know that i have a bad memory...ive spent a couple hours tonight and prolly on and off for the past few days..trying to figure out when i started the depo shots..because my period has actually started and im trying to figure out how long ive been without it..the shot is working ..but i really was at tantrum level today about the whole issue and ready to go and tell my doctor that the shot isnt working...i just struggle so much with the whole period thing and the issues are very deep and troubling and the whole thing is a major trigger..and its just been a non consistent issue for the past like month...cramps here and there..a little bit of spotting..but the past week it all intensified..and the cramps are coming with a vengence..but i cant remember when i started the shots..has it been six months..nine months ..or a year..i suck so badly at recalling things and i cant match up time frames correctly .. and so trying to remember is causing me to forget even more and doubt all of it..and i feel stupid for not being able to remember the simple stuff..i forget the important stuff..the non important stuff..and it just ..its hard..it makes me feel bad...