I had breast enlargement with silicon implant now i feel something wrong in my left breast, does ultrasound enough to discover breast tumor ?

Depends: It depends on what your doctor feels on their examination. If the ultrasound findings do correlate with your doctor's examination, and the ultrasound finds a benign process, then ok. If the physical exam is more concerning, then sometimes mammogram and breast MRI are indicated. Review your ultrasound findings with your doctor, who may need to discuss with the radiologist if you need more testing.

Depends: If the ultrasound detects the lesion you are describing, they may be able to biopsy the lesion to see if this is malignant. In the unfortunate event that this a tumor, based on your age, you will likely need an MRI of the breast in addition to a mammogram. Make sure you see a doctor who can help determine what the next necessary steps will be.

Start with mammogram: The gold standard in screening is a mammogram. You should have a mammogram first. Mri is also useful in detected whether you have a silicone leak from the implant.