What Causes Discharge Of White Liquid From Left Breast?

I have white liquid coming out of my left breast, I am petrified because i had sex 1 or two days ago. I am 17 years old and and 5'6 We were both fully protected though. I was on Birth control and he had a condom, put on right and everything What could this be, I am petrified. Is it the birth control? Is it all in my mind (because im ao scared) or is it normal? Please answer back very soon.