what do you mean? As in time of day? Personally I pull them after the 12hrs of light, figuring that time is photosynthesis time.
If you meant if you let it go longer, then yes, that changes the high, and in fact, if this is your first grow (good job by the way, way better than my first grow, course that was in the late 80s, lil different then)
But anyways, i'd suggest NOT pulling the entire plant, pull maybe 3/4 of it, and letting the remaining 1/4 go another 6-10 days, and see if you prefer the high of the plant going a lil further, reason I say this, is I prefer my herb fairly ripe, some don't, but the high changes fairly substantially if you let it ripen longer. One thing is for certain, most varieties will pack on a lil more weight the longer you go (usually the lower buds fill out), especially sativas