Lactating and birth control pill tri sprintex

Miriam • wife and mother of one awesome 4yr old daughter. Expecting January 20th for my second baby !!!!
I was put on tri sprentic since I was not ovulating for 3 months April being my last. Well this being the second month on the pill and no I'm not pregnant, I am lactating! Any one else have had this happen to them. I'm just curious if it's the pill or if it's me? I am going to the doctor this morning not my gyno who put me on the pill but my regular doctor.