Fever when pregnant

I'm six weeks pregnant, and when I was four weeks, I got really sick with an 102.6 degree fever. I didn't know I was pregnant at the time though, so I didn't call a doctor. I have my first ultrasound in two weeks, but I didn't mention the fever when I scheduled the appointment. Now I'm wondering if I should call my doctor again and mention the fever I had, even though it was two weeks ago, since fevers can be dangerous when pregnant. Thoughts?