Suggest Remedy To Get Rid Of Dark Patchy Spot On The Skin

hello doctor,
i am a 29 years old female,married. recently i developed some dark patchy spots on my cheeks which are not visible at once but when observing carefully. i am noticing the spots since marchof this year, but they are not as dark which can be seen quickly.what is the cause for that? i recently used Lotus whitening lotion,spf 25 , which made my skin further darker.now i am using Jovees fairness cream and lacto calamine for the spots and lemon juice once a day...kindly give me right way to clear the spots. as they are not visible easily,i want a quick treatment before they r seen to others.