Also, for some that don't ovulate normally and may have too short of a luteal phase (later part of after ovulation) and thus have luteal phase defect then the clomid causing ovulation allows for adequate progesterone production to sustain the luteal phase length and thus the cycle can be longer than normal while actually regulating the cycle. What I mean is that if one doesn't normally ovulate then there is no corpus luteum (collapsed follicle) left over from ovulation which is what produces the progesterone levels that sustain the remainder of the cycle. If one takes clomid and ovulates then there is now a corpus luteum producing progesterone levels that sustain the cycle and so AF won't start until that level drops and prompts it whereas when one does not ovulate they may not have a progesterone level high enough to cause that drop and thus AF starts too soon or AF never shows without being induced.
Hope that makes sense!
Basically though it is very normal and even pretty common for clomid to cause a longer cycle.
I was in that camp with PCOS, annovulation, and a luteal phase defect (where my progesterone was too low to sustain the cycle due to not ovulating and thus I would start AF too soon). My cycles went from 28 days approx. to 32-35 days on the clomid. I also had several clomid cycles where I did not mature a follicle to 18mm and thus did not ovulate and yet my cycles were still longer because my body was at least taking the time to try to mature one which pushed my follicular phase out and made my cycle longer.