Antidepressants and sex

My oh is 33 and taking an antidepressant in a small dose and has been fine until the last few days, we are ttc our first child together and bd'ing regularly while im ovulating but yesterday and a few days before that he couldnt ejaculate and its starting to worry both of us incase we never conceive, his doc said the meds hes on shouldnt do that to him but im getting really worried 😢