Two months of on and off spotting

Mid December spotted from dec 11-24. Stopped. Started Jan 2-9. Stopped. Now again Jan 20-today. Today there was black like clots. Only brown/pink when I wipe. Dr tested on dec 30 by blood work. No pregnancy. No infections. Husband has been in me without condom but then uses one before orgasm. Really not sure. No other forms of birth control. Just condoms.  Very annoyed with what seems like always spotting. Anyone else have this? Thoughts??