Depo has ruined me please HELP!!

Hello guys , my last depo shot was on April of 2015 I have been ttc since October with no success I just now started having semi-regular periods in December this month however I had mid cycle bleeding on my OVULATION. day which lasted several days and yesterday my period was due and I did not begin , was that mid cycle bleeding considered my period or could I be pregnant we been trying so hard with no prevail :( I am becoming so depressed depo has ruined me .. I don't feel I have any symptoms other than loose stools with sharp pains , what should I do ??