at what point do you involve a doc?

Hi ladies! AF is fashionably late (CD 36 on a normal 29/30 day cycle), all negative tests, and no sign of pregnancy or AF for that matter. CD 22 I had sore nipples and this week a few days had bleeding gums/metallic taste in my mouth. 
I'm trying to gage how concerned I should be. At what point do you involve a doctor to see if something's wrong/I'm not ovulating or something?
Thanks in advance.