My resting heart rate is consistently about 100 bpm?

In the past I've never had a fast pulse, but recently my pulse is consistently at least 100 bpm and sometimes up to about 116 bpm. The other symptoms I have are intermittent headaches that are localized, but vary in location and last for a few seconds and I feel like the room spins when I recline, but not when I sit up. I'm making a doctor's appointment tomorrow, but does anyone know what could be going on?? Or what tests the doctor might do to figure it out?? Thank you!