positive opk

so I got my positive opk today and horrible cramping but no EWCM. I had negitive opk @11am yesterday but it was close. then I had EWCM around 8pm last night. I only test once a day so idk what my chances are if we BD last night but won't tonight. tonight he is away working until who knows when, then has work at 4am. BD is the last thing on his mind tonight. What do you think the chances are? if we BD at midnight last night?