Second BFN

Victoria • Ttc #1 27 yo married with 2 "bonus" - daughters peace love happiness
I just took a second pregnancy test today after being 5 days late and I got a BFN =[ I've only had regular periods since November 2013 so I'm worried, even though we were trying during my fertile window, I'm not pregnant and I'm going back to being irregular (PCOS). Suggestions? Ideas of what could be happening? How long did it take for everyone to get a BFP?