Hi Deepthi, Try increasing Mg++ ion concentration by adding either MgCl2 or MgSO4 salts (optimize by increasing 0.5-1mM salt concentration at a time) in your PCR reaction. Optimize it first on a positive control such as DNA from Hela, Ca Ski, SiHa or any other HPV positive cell line.
I also use the Master Mix 2x from Promega or Bioline or other company, they work well. I agree with Sheeba for positive control but watch out the contaminations