Age and body mass index (BMI) alongwith sex (which you have indicated in your question) all play parts in diagnosing such pains in the pelvic region. Elevated BMI can lead to increased pressure on the joints around your pelvic area. The resulting extra stress on these joints can cause inflammation and pain not only during kapalhati but also regular exercise.
Please mention your body weight, waist and the way you practice kapalbhati so that I can correlate and suggest you accordingly. For the time being, I would suggest you to discontinue the kapalbhati practice, completely to prevent further aggravation of the issue.
