What happening to me???

I apologize ahead of time for tmi...so here it goes. For the past 2 months, my periods have been off, Either a few days early or late, and very very light. Like 3 days of spotting. Now, my period is due in a little over a week and I am in pain. There's a tightness in my left side close to my hip. I'm pretty sure I passed my ovulation time already, and this doesn't feel like my usual cramping. I'm becoming a little concerned. My husband deployed in january, so it's not like I could have conceived this month. Any ideas? Has this happened to anyone?