My doctor just perscribed me with birth control for my acne and told me to start taking it once I get my next period. The trouble is last year I lost my period for 7 or 8 months...I recently got it back these last two months but my eating disorder has gotten bad again and now im getting cramps but no menstration. So what happens if I take my birth control without getting my period?

Please I need answers because I cant ask my doctor (if she knows I lost my period she'll take my adderall away), and if I dont take them my mom will notice.