There are quite a few other features that factor into the pear/hourglass body shapes. A two inch difference between your bust and hips could put you in either category depending on these other features.
If your shoulders are narrow, more so than your hips, and your arms are very slender, then you're likely a pear.
Hourglass figures tend to have much meatier arms and their shoulder width is essentially equal to their hip width.
Also, don't rely solely on measurements - this can be misleading. For instance, I'm a very standard hourglass shape visually, but my hip measurement is almost 2 inches larger than my bust. This is because my behind is very rounded. But from looking at me, it's very clear that I have an hourglass shape.
And speaking of the size of one's behind, there is also the S curve to consider. If in profile, you have an S shape (your bust sticks out, your stomach goes in, and your butt sticks out again more or less as much as your chest) then you're likely an hourglass. A pear's behind will stick out a lot more than their bust.
If you're still confused, then you may not fit perfectly into either category. But it doesn't really matter - you can utilize tips from both shapes. Just use what applies to you. :)
Good luck!