Why Am I Gaining Weight And Having Irregular Periods?

i have not got my periods from Oct10 onwards. am very much worried. now we are planning for baby also. but, not got period yet. consulted doctor today, she has given me Deviry tablets. and am also taking folic acid from last two months. and am continuously gaining weight. am 32years, 5.6" height, and weigh 86kgs. please help me