Your melting curve showed 3 sharp peaks. we can see small and broad peak near 65 ºC. It may related to primer-dimer (the lower temperature), we can also see another sharp peak near 75ºC and 88 ºc. You should if they are 3 pcr product in gel electroforesis. Should use biorad software or related to see well if the weak band appear in the gel. If you use silver green dye try to decrease concentration.

My primer is running out soon. Hence, I try to use lower concentration

Dear Lim,

I think, your total template amount and primer concentration is too high. Decrease your total template in per well. As it is fluorescent based quantification, huge amount of template sometimes gives you false positive result. I use only 2 ng of total template and 200 nM of primer for 10 μl of reaction. Kindly, once go for lower amount of template and i hope it will work.

Hi,

Try the above given modifications, just before doing it-  u need to see the products on gel, which gives u a clear idea on what happened to ur reaction.

If im right I suspect a strong nonspecific product amplification along with the desired one and a dim primer-dimer in ur reaction by seeing that image. 

Ct values caused by primer dimer alone can be neglected (usually they appear at 34 or 35th cycle in even with routine reaction component levels). For optimum quantitation of desired product, one must adjust reaction accordingly, each template type/primer system may have their own unique performances which is apparent. 

While reducing the component levels (primer for example) in reaction, dont give a drastic change but go for maximum of 20% to 35% reduction in ur case by gradient setup at each level varied by 10%. 

Do great, gud luck!