Dutasteride and planning for a baby?

My husband takes Dutasteride and Minoxidil. We would like to start a family. My primary care doctor said we could try 5 days after he stopped the medicine, while our dermatologist said 6 months. 2 questions 1. When could we start trying? We don't want to wait 6 months if it's not necessary. 2. Will a semen analysis help detect the drug levels in his semen? we are wondering if that could help us determine when we can start trying