First, let me ask you to turn off your caps as it seems like you are shouting. k?;)
Now let me refer you to
this post.
Typically a yellowish color represents an infection of some kind or another. What kind is impossible to tell without an exam by your doctor.
Can it be transmitted to your boyfriend? Again, you would need to know exactly what infection you have. Whether it be a yeast infection or an STD (STI) is impossible to tell without an exam.
Your best bet is to make an appointment with your health care provider to give you an exact diagnosis.