My understanding is that you can. The LH
means your body is getting
ready to ovulate, but sometimes it can "back down", kinda change its mind. You hear sometimes of women getting a positive OPK twice in one month. I was also using OPK's, and have successfully conceived with them 3 times now. Even though they say not to bother testing after getting a positive, in April I did anyway, and it stayed positive for 3 days...