Pms or pregnancy

Hi, I'm having troubles if I'm pregnant or not. I had my first sex on March 1 and I was supposed to get my period on the 12th. I have irregular periods tho I always have 28-31 days interval. Until now, there is no sign of blood in my pads and I'm having sporadic cramps in my lower abdomen and tender breasts. There is also itching and burning feeling on my vag and I'm having some milky odorless discharge, like cottage cheese. I also have hyperthyroidism. Please help me because I'm new to this.