Okay, this is going to be a bit long so I apologize. My husband had a vasectomy back in November 2013, and even though he never got checked to make sure he was sterile, we seemed to be in the clear. But now my period is 6 days late and I've absolutely NONE of my usual PMS symptoms that my AF is on its way. I've been a bit tired, have almost no appetite (which is not me at all, I love food), and I've had more head aches than normal. I took a pregnancy test yesterday, when my period was 5 days late, and it came up negative. I bought a couple more H.P.T.s to test again in a day or two, but I honestly feel like I'm losing it. If I'm not pregnant, what else could possibly cause a halt in my menstrual cycle? I have a normal 28-29 day cycle and I ALWAYS get my PMS symptoms, so something definitely seems to be amiss here. Did my husband's vasectomy not take and we've just been really, really lucky these past two years? Or could there possibly be something medically wrong with me?