My period is supposed to start in 2 days. I'm having really bad cramping pains (which I've never had before) they started about 3 days ago. And my nipples are Super sensitive. (Never happened before either) I've been experiencing random headaches. Lower back aches. And a few other random aches and pains. My SO & I are trying to conceive and had sex nearly every day of my fertile window. So what do you all think: PMS or something else??