Easy to check if you need the truss rod adjusted. Hold down the low E at the 1st fret and the 14th fret, and then look at all the frets in-between. There should be a very tiny gap at the 7th fret (like a business card or so amount). If there's more gap, then tighten the truss rod, if it's touching the fret then loosen it.
Any chance you just got a bad pack of strings?