What Causes Delay In Period With Chest Pain After Protected Sex?

hi, i m having delayed periods since last 3-4 months. this month also, i did not have my periods yet. Though there had been lot of travel and stress in the previous month. i m having white discharge since last 10-15 days with chest pain. no other symptoms. apetitie is normal. i did indulge into intercoarse but was protected. kindly suggest if i m pregnant or not. age 27