Need a good advise ??

The doctor gave me medroxyprogeateron 10 mg on jul 28 they make me a blood test before just to make sure i wasnt pregnat and i havent had my period since feb 28 the thing is i just start taking the pill 5 days ago and still not signal of my period idk if maybe in the time thru july 28 and august 31 could i be pregnat now or idk what to do ?? And i dnt have money to buy a pregnacy test in the pharmacy or the medicine doesnt work for me idk any comment HELPPPP pleaseee???