Maybe a stupid question ...

Jo • Both 41...TTC for too long
But I got my (+ opk) smiley face Sunday & Monday and today it was a - opk. We bd both days and going to later on but my question is this... I got the - and have cramped on left side... Clearly ovulating today... Is tonight's bd too late? How long does the egg live to fertilize once you get that - opk after the + ? 
​We bd on CDs 7,9,11(+opk), 12. (+opk) and today is 13cd. 
​This is exhausting lol any input appreciated thanks!