Aching Legs and Zyrtec-D

I have been taking Zyrtec-D oral pills for about 6 years. Six months ago there was a mix up when I called in my prescripton and I received Zyrtec rather than Zyrtec-D. I took it for a month or so and realized that it did not work as well as the "D". I went back to taking Zyrtec-D. I usually take only 1 pill per day even though it says to take two.

My problem is aching legs. I am not able to sleep at night because of the constant ache. When I look back I do not recall having the aches to where they kept me up at night when I was taking just Zyrtec. The past couple of days I have taken 2 tablets per day, one in the am and one in the evening, and now my legs ache constantly, morning, noon and night. Could this be from the Zyrtec-D?