Waswasa is Satan’s whispering to you. First of all, you should know that it is from Satan. The Glorified Allah commands in Quran:
“And indeed We have created you, [O Mankind], and given you [human] form. Then We said to the angels, “Prostrate to Adam”; so they prostrated, except for Devil. He was not of those who prostrated.[Allah] said, “What prevented you from prostrating when I commanded you?” [Satan] said, “I am better than him. You created me from fire and created him from clay.” [Allah] said, “Descend from there, for it is not for you to be arrogant therein. So get out; indeed, you are of the debased. [Satan] said, “Reprieve me until the day they are resurrected.” [Allah] said, “Indeed, you are of those reprieved.” [Satan] said, “Because You have perverted me, I will surely sit in wait for them on Your straight path. Then I will come to them from before them and from behind them and on their right and on their left, and You will not find most of them grateful [to You].” (Al-A’raf/ The Elevated Place 7:11-17)
Satan only whispers to those who are on the right path. Therefore, Satanic whispers show that what you are doing is right! From the following verses we learn what we should do in such cases:
“And if a mischief-making whisper comes to you from Satan, then seek refuge in Allah. Indeed, He is The All Hearing and The All Knowing. Indeed, those who protect themselves, when an impulse touches them from Satan, utilize their knowledge; and soon they gain insight.” (Al-A’raf/ The Elevated Place 7:200-201)
As we can understand from the verses above, Satan will keep whispering people; but you shouldn’t buy that. People who fall for waswasa make various mistakes in worships and other issues, and cannot enjoy their worships. Satan’s whisper may lead people to wrong or superstitious ways. It may even cause mental sicknesses. Therefore, relax and do not bother yourself. In order to prevent this; turn to Allah by reciting “A`udhu billahi min ash-Shaytan ir-rajeem”, and the chapters Al-Ikhlas/The Purity, Al-Falaq/The Division, An-Nas/The Mankind together with their meanings.