Check for juice in the air vents in the removeable cartridge. Take it off and blow hard through the mouthpiece over a paper towel. Condensation and rogue juice ends up there after a while.
Since you've had it for a few weeks it might be time to perform the all important dry burn
Sometimes the wick is so clogged it makes it hard to draw properly and for that it needs cleaning. There's too many methods to mention, but I think the simplest and fastest way is to dry burn it like so:
1. Disassemble the atomiser from the battery and the cartridge from the atomiser.
2. Blow out as much exess juice from the atomiser as you can.
3. Screw the atomiser back onto the battery after you have dried the threads on the atomiser where it will screw onto the battery (I used a twisted up corner of a paper towel so it makes a point for this).
4. Fire the atomiser. Keep pulsing the button on the battery while you gently blow into the atomiser. It will smoke quite a lot but it will subside in a minute or two. You want to keep going until you see the wick in the middle is glowing a dull red. Maintain this dull red glow for 10 - 30 seconds then that's it.
5. Profit!
I stopped using egoTs a while ago but I've solved most problems with the ones I did use by dry burning them every once in a while but I used VG with them so they gummed up faster than most people's would.
Good luck with yours though
