i agree with stacey, i had a positive opk at 11dpo and two days later got a positive on a HPT. that was 4 years ago. good luck!
yes you maybe pregnant as opk's can pick up hcg so do a pregnancy test and see how you go :)
You could have been gearing up to ovulate before, and never did, I've had this happen a couple of times, you could be ovulating a 2nd time, but it's pretty rare for that to happen, definitely BD just incase, and expect your period to be later if you are just ovulating! If you were pregnant, and it was picking up HCG it would be picking up on a HPT, my positives on OPK's weren't til about a week after I got a positive HPT! Good luck!