Could I be pregnant?

I usually get my period pretty regular, but I haven't gotten my period in two months now. When I got my period three months ago, it lasted 3 days and was very light, and I usually have my period for 5 days with moderate bleeding. I don't feel like I'm even about to get my period either. I've been really tired lately and just felt pretty blah. Been nauseous and my back hurts. My fiancé had a vasectomy 8 years ago. There’s no cheating on my part, so there’s no possibility of someone else. Should I worry about this? Any suggestions as to what's going on with me?

It sounds like a long shot for you to be pregnant but you might want to read the info at the link below. I wouldn't worry about it but I would try to find out what's going on. There are other things that could produce those symptoms beside pregnancy. It might be worth a visit to the doc if it continues.

http://www.plannedparenthood.org/health-topics/pregnancy-4250.htm