Hi.. It is not true.. Fertility depends on developement and release of normal ova into the fallopian tube and by all conditions that favors normal fertilization of the ova and development of embryo in the womb.. It is not in any way associated with presence of painful periods.. So relax.. If you are looking to see if you are fertile or not, you may visit a fertility clinic and undergo all the test advised by them.. Only the evaluation in this clinic can diagnose if you are fertile or infertile... All the best..