Hi, I Had Unprotected Sex With My Bf On 22may

Hi, i had unprotected sex with my bf on 22may and had taken unwanted72 on 23may. My periods were supposed to come on 1april but i havent got my periods untill now. I took pregnancy test today morning but it was negative . sometimes i feel dizzy and have heavy breathing and also have abdominal pain every now and then . What should i do ? Why my periods are late ?