Birth control and questionsk

So I am taking Mono-linyah which is my daily pill. I take them but sometimes I forget to take them or I don't take them on time. It gives me my period every month. I had my period a couple weeks ago. It ended the day before me and my SO had sexual intercourse and today I started to notice a really light pink discharge yesterday and today. I've been ignoring it but it's not normal for me and I'm wondering if any one else takes this and maybe knows more about this BC then I do.