You go by the FIRST +OPK. The ones after that just mean that the LH is just still in your urine, but that very first one indicates you've had your surge, so you should O 12-36 hours later. It happens to me too. I have pics of my OPK posted via the link in my signature if you are interested. Here is a good bit of info to explain it more:
https://www.peeonastick.com/opkfaq.html#4
What if my OPK is positive for several days in a row? It is possible, in a normal ovulation, to have a positive OPK for several days in a row. This is because LH peaks (surges) about 12-36 hours before ovulation occurs, and then dissipates. So, you could theoretically detect this high level of LH with positive OPK's from the time it begins to the time it dissipates-- over 36 hours.
It is also possible that your body is "gearing up" to ovulate, and you have an LH surge-- and then, for some reason (such as stress, illness, travel, or random fluke), your body fails to release an egg . . . then tries, tries again ASAP with another, or overlapping, surge. If you see a positive OPK for longer than 3 consecutive days, your egg is probably just having a little trouble getting out of the starting gate. If this happens to you occasionally, it's no big deal. If it happens a lot, talk to your doctor.