You need a different mic.
The headphone jack makes up to four connections with the device you plug into it; it is a TRRS device, which stands for Tip, Ring, Ring, Sleeve.
If you do not understand, please look at this product:
http://www.amazon.com/PWOW-Micropho...1&sr=1-15&keywords=Headphones+with+Microphone
and look closely at the part that plugs into a device (the four connections on the plug are TRRS).
So, if I draw the plug with text, < | | | |----- , it would be < T | R | R | S |----- .
Now, what do TRRS connect to? Left, Right, Ground, Mic.
< L | R | G | M |------
A left earphone connects to L and G. A right earphone connects to R and G. A mic connects to M and G.
Many external mics DO have this little 3.5 mm plug but DO NOT have the kind of tip|ring|ring|sleeve configuration designed for our phones and tablets. Rather, they often have just tip|sleeve or tip|ring|sleeve. For a mic to work with our common devices, I imagine it would have to have its plug configuration something like this: <NC|NC|G|M , where NC is Not Connected to anything.
Look at this external mic, which IS designed for what you want and even allows you to plug in a set of earphones:
http://www.amazon.com/Dayton-Audio-...2114804&sr=1-5&keywords=Microphone+for+tablet