You might actually have the flu, when you're pregnant your body's ammune system is lower so it's easier to get sick.
If you have a temp 100.4 are very light headed, or vomiting you should call your OB/Midwife. I got the flu with my first and was sent to the ER they hydrated me with an IV and gave me nausea meds so I could keep food/water down.
When you feel extra crappy like this always give your OB a call so they can decide if they need to see uoi