Need advice!

katey
So I had originally thought that I ovulated on saturday, due to a positive opk. Well I took an opk this morning and it was super positive! so I haven't had sex since Saturday. I should have known better bevause last cycle, my positive opk was super positive. Do you think if I have sex tonight I have a chance? When I got pregnant with my second, we only had sex once on the day of ovulation. Give me some hope!