True statement about Minipill is:

Ans. is a, i.e. Irregular vaginal bleeding may be a side effectRef: Leon Speroff 7th/ed, p922Minipill can be used during lactation (i.e. option "c" is incorrect).It is not used in combination with other pills therefore option "b" is incorrect.Minipill"Ectopic pregnancy is not prevented as effectively as intrauterine pregnancy. Although the overall incidence of ectopic pregnancy is not increased, When pregnancy occurs (with minipill use) the clinician must suspect that it is more likely to be ectopic. A previous ectopic pregnancy should not be regarded as a contraindication to the minipill." - Ref: Leon Speroff 7th/ed, p922So option "d" is incorrectMain side effect of Minipill/progesterone only pill: Irregular bleeding and amenorrhea (i.e. option "a" is correct).Pearl index-3%