[Advaita-l] Effects of incorrect Mantra Pronunciation

[Santhosh Nair]

Hi,
I have a doubt about mantra recitiations. Some people say that if someone pronounces the words in a mantra incorrectly, it could bring adverse effects. Is this true? I used to chant mantras (Gayatri, Mahamrityunjaya, etc.) And I think I did this in an incorrect manner (including the position, diretion i faced, and the timing. If it has any ill-effects, is there somethiig I can do to correct it? Currently I chang only Vishnusahasranama and Narayaneeyam (3dasakas/day), at 7 am.
Please do let me know because now I am suffering from various physical problems.

Thank you.