Day and a half of bleeding.

My periods are so short, a day of super heavy bleeding followed by a half day of medium bleeding and then I'm done. It used to be awesome but now that we are on cycle 7 of ttc our first, I'm starting to worry that my cycle is just too short. I average 23-24 days each cycle. My doc didn't seem concerned but she also wants us back in January of we haven't gotten lucky.