My boyfriend and I had sex 2 weeks ago; it was safe sex either. But it was rough and I even had a fever after our sex. I'm supposed to be having a period last week but I am now one week delayed. I took a pregnancy test a while ago and it shows negative.

My cycle changes every month, sometimes it's 19, 30, 25 and so on. I'm sometimes delayed without having sex. I'm even having cramps and sore breasts so I thought I'm going to have a period but I'm not.

Last month, I have a schedule change for my job. I'm now on a night shift. And I've been stress several times because of my job. As I searched, stress can affect the menstrual cycle. Can someone tell me what's going on? Because I'm really worried