I had my first day of my last period april 16 then i went off birth control pills. i then had cramps and what i think was a light period starting may 25th for three days. was that probably my period or withdraw bleeding?

Light Bleeding: More detail is needed. However, there is a concern about a possible pregnancy since you appear to be late getting your period. Your periods should be regular unless you are pregnant or you have a medical condition. Periods happen because there is a drop in hormones that causes a slough of a portion of the lining of the uterus. Consider going to obgyn ASAP for further eval.