Periods missing. To induce my periods?

Okay so I haven't had periods from last 6months and i am not even sexually active . I have masturbated once or twice tbh but i guess that has nothing to do with this . And I recently stared taking iron tablets which has helped me in getting period stains but not periods. My mother says I don't have to go to gyna and it'll be alright soon because that way I'll have to relay upon medicines for inducing periods. :/ help me i am really concerned . Yes i have lost and gained weight and have got stretch marks on my thighs and at sides of my tummy , they are reddish in colour . Does this have to do anything with my periods? Help me ! How to induce my periods? This is the longest gap I've ever had till now . Have skipped periods in past but that was for one or two months only .quick Reply would be appreciated . Thank you :)