Flu-like symptoms first trimester?

This is my first pregnancy and I am about 2 1/2 months. The first two months went fine but the last week or so I have noticed increased fatigue and hot flashes at night. Some of these seem to be flu-like symptoms except that I have no fever, no body aches, and have not been coughing or sneezing. I do experience occasional headaches (which was a problem prior to pregnancy).

Are these flu-like symptoms all a part of normal pregnancy or do I have cause to be alarmed?