Pinkish brown discharge?

During my fertile window? I never really have discharge unless its clear so idk. I was wondering if it could be something different than implantation bleeding or if it could be that? My boyfriend kept asking me "what if you get pregnant" after we had had sex like 3x but said he a) didnt nut or b) pulled out. However it is frustrating me he keeps asking me that. I feel kinda :/? Weird? I feel like im venting now. I feel kind of violated if he did nut in me and is lying about it. I just wanted to know if this discharge is common during this time.