3 Month Birth Control

Hi! So I've been on the "normal" pill for like 7 years and have recently started experiencing some (abnormal) cramping (pretty sure its a recurrig cyst but...). Finally went to my OBGYN and she switched my normal pill (a "period" every month) to one that makes me only have a period every three months. Wondering if anyone else has been on this birth control and if so whats the sode effects? Should I experience side effects if i've already been taking a form of hormonal birth control? Is this just something to ask the pharmacist?