Someone help me clarify some things about birth control?

Okay, so I have a few questions that I have asked before but I can’t get a straight answer. 1: I have been on my pill for 1.5 years, I haven’t had any crazy bad side effects, the last two months my pill has given me pink or brown discharge at random times 1 or 2 weeks before my withdrawl day, SO does that mean the pill isn’t working for me?

PART 2: My boyfriend and I recently started to have sex without using a condom, he does not finish in me, if I get my withdrawl on time and it’s my usual heavy/normal flow, does that mean I’m not pregnant? I had dreams about fish and being pregnant so I’m anxious. I understand with sex comes a chance of pregnancy. But I’m asking about it with the pill and the bleeding. Whoever takes the time to answer, god bless you cause I’m so confused