Dear Mrs. Madhu,
I appreciate your concern over your weight gain. it would have been nice had you mentioned your height & the amount of weight you have gained recently? being vegetarian doesn't guarantee a stable weight.
are you eating a balanced diet? is there an increase in your carbohydrate
intake recently?since its summer are you taking a lot of juices which could lead to easy weight gain as they are loaded with sugar.
if you are very sure about no change in your diet pattern and lifestyle, then other possibilities could be hormonal
imbalances like hypothyroidism
. only in such cases medications will help that too after confirming diagnosis from a physician. in rest of the situations balanced diet & exercise will help you tremendously.
stop worrying because stress
is a major factor for weight gain. take care.