I got an increased level line on my opk last night and Glow predicted my ovulation to be today and there were physical signs that it was soon. We had sex last night just in case, and, this evening when i tested, the line was lighter than yesterday.. so I'm thinking my surge might've been earlier today.. is it possible for last night's bd'ing to be sufficient? I will do another opk tomorrow just in case, but just curious if doing it 12 or so hours before the surge would be OK.