Final answer:
They should continue trying naturally for up to one year. Tracking ovulation with BBT and ovulation predictors is recommended, and clomiphene citrate can help if there's an ovulation problem.
Step-by-step explanation:
For a 27-year-old woman (G0) who has been trying to conceive for 3 months with a healthy history and a healthy partner, the next step in management would typically be to continue trying to conceive naturally for up to one year. Since her menstrual cycles are irregular, possibly indicating anovulatory cycles.
She could start tracking her basal body temperature (BBT) and using ovulation predictor kits to identify potential ovulation periods. In case of a diagnosed medical problem inhibiting ovulation, medication like clomiphene citrate could be an option to stimulate ovulation.
If after a year there is still no success, it would be advisable for both partners to seek a fertility evaluation. An endocrinologist or fertility specialist may recommend tests, such as semen analysis for the male and a hysterosalpingography for the female to assess for possible blockages in the oviducts, or other reproductive health assessments.