Hi Dr I Am A Mother Of 3 , An

Hi Dr I am a mother of 3 , an would like to try n over the counter diet pill for weight loss. I really don't eat that much , but I keep putting on pounds . All of a sudden my weight is getting higher . I am 40 years old ,5ft 1in n weight 140, last month I weighed 137, I started at 129 then escalated to 140 within a month or two. I do have my tube cut n tied . I don't understand.
Thank you