LH surge > 24 hours??

Has anyone had an LH surge lasting longer than 24 hours? My opk was positive last night at 6pm (several days earlier than usual), positive again at 6am this morning, and still positive at 7pm this evening. I'm confused as I usually only get one positive. Can this be normal? Any thoughts? I'm already stressed as I used lube on Sunday thinking it was safe til yesterday, but now I'm afraid I've killed good sperm the with this early ovulation. 😕