- Not pregnant or breast-feeding; woman of child bearing potential should have a negative pregnancy test (serum beta-human chorionic gonadotropin [HCG]) within 7-14 days of starting cycle 1 of treatment; woman of child bearing potential should have a negative pregnancy test (serum beta-HCG) within 10-14 days of starting cycle 2, the start of lenalidomide treatment (i.e. days 14-18 of cycle 1), and an additional test within 24 hours of starting cycle 2 treatment