Period question

Elizabeth

Hey ladies. My baby is 7 months old today and is exclusively breast fed. I've been working from home, so she is latching on directly. My period is 3 days late, yet I just took a test and it was negative. I am on the pill, btw. Never have I missed a period since being on it since December. I've heard that you don't get your period when you latch baby directly. Is this true? Thanks!