That model is two years old. So, I'm guessing you bought yours perhaps 18 months ago, more or less. The battery could indeed be swelling. And yes, as I said, touchpad issues are often the first symptom of a swelling battery, because the touchpad is on top of the battery. If it were my laptop, I would open it for inspection as I explained. Or, if it's under warranty, contact Dell immediately. Even if the battery is not the cause, trackpad malfunction would be a warranty item. There have been reports of touchpads on some models not being adequately grounded, and Dell can remedy that.
I am sure that I can't be the only one that has this issue with my trackpad: If it wasn't for my wireless external mouse and / or touchscreen, I would be totally helpless. Dell makes incredible and efficient machines, except for this terrible excuse of a trackpad, which honestly does more harm than good.
Trackpad almost unusable