Pregnant? Period? Or what?

I am always pretty regular with my period. Always around a 30 day cycle. I had a period that started on April 6th and lasted my typical 5 days. I have been having a lot of unprotected sex. I then seemed to have started my period April 27th. Wasn't very heavy, it was light bleeding for around 6 days and then over the next 4 days I had some spotting. I have never really had a light period or spotting like that before. Now I am severely nauseous and am having strange aversions to certain food smells. I wake up in the middle of the night feeling like I am going to puke. I have had headaches the past couple of days that aren't very bad but they wont go away. I have been very bloated and have had some light cramping and lower back pain. Did I just have a very strange period for me, do you think I could possibly be pregnant, or could I just have some strange virus? Any help would be appreciated.