[There are three possible effects that are demonstrated after an adjustment;

Person feels no significant change.
Person feels a change in symptoms with immediate improvement.
Person experiences new short-term symptoms associated with functioning in a new structural position.

Long Answer: Responses to the adjustment vary from nothing, to muscle soreness, and from fatigue to a feeling of euphoria. Due to these individualized responses all patients are given a list of things they may experience so they are familiar with what responses are normal to expect. Due to the significant postural rebalancing that occurs with the upper cervical adjustment people will often feel stiff and sore for 2-4 days as the body adapts to its new position. This discomfort is usually associated only with the first and/or second adjustment.]
http://www.nucca.org/faq.php

Plenty of fluids might be a good idea after adjustments as well as after PT or massage.

Did you only have the c1c2 adjustment?
Did they do any other adjusting or treatment/therapies?