Talk to Gynecologist on Missed Period From 2.5 Months

Respected Doctor, I am currently 23, started my periods at the age of 12. Everything seemed normal at the beginning. I didn't use to keep track of it. Then, after some time, in my teenage probably, my period cycle started to get irregular. I kept good care of my diet. But usually the cycle took 40-42 days. Currently, the problem is, that I haven't gotten my period since November 31st, 2019. I kept on waiting in December, it pained and showed all the symptoms but the bleeding. I took a pill, to stimulate the process, known as 'Gynaecosid'. So, its been 2 months now, I have taken a pregnancy test as well and the results were negative. Due to this condition, I am facing extreme mood swings and a lot of stress. Please help me as soon as possible. Regards.