tell me the number of times patient 2238 has had a lab test for carcinoembyronic antigen (cea) since 02/2104.
select count(*) from labevents where labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'carcinoembyronic antigen (cea)' ) and labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 2238 ) and strftime('%y-%m',labevents.charttime) >= '2104-02'