Cd15 ovulation or implantation? (Tmi)

I average about 31 day cycles. Im on cd15. I Quit smoking for good about 2 weeks ago. Tonight, I had a rush of fluid in my panties with pink(blood) fluid. Wiped and pink again. Put on pantyliner and red string blood on panty liner 1 hour later. We bd'd 2 nights ago. Using preseed every time now. This has never happened before. Ive been calmer and trying not to stress over not having conceived yet(about a year this month) Im just needing some advice please.