Loud engine when accelerating
 

Last year I bought a 2000 Honda civic from a reputable car dealership where my dad works. The only owner before me was a little old woman and the car had less that 70k miles.

Have had no issues, but last week upon starting, I noticed it sounded louder than usual. When driving at lower speeds it sounds normal, but when I hit the gas a little harder it gets louder.

Due to my previous lemon vehicle and my far drive to work, I am super paranoid. Drove it the last two days to and from work with no issues.

Any idea on what it could be?