Here's my plan

I'm cd 11. We bd'd cd 7&10 so far. I have gotten positive opks cd 11&12, 13, 17, 18 and 19. I'm so confused but I'm assuming when my cycle is shorter I ovulate earlier and when it's longer I ovulate later. Should I just make sure we bd on those days? I was going to bd every other day but I feel like it's not enough