I suspect that your first O was a fake O and this may be the real deal. A pos OPK does not necessarily mean you ovulated, all OPK tell us is that yoru body released a little surge of hormone that was detected in your urine. You can release this hormone even if you're nowhere near ovulation. More commonly, your body starts to ovulate and then decides not to so you can get a false positive, then a real positive later on.
You can't get a pos OPK for a pregnancy test until after a real pg test comes up positive, so if your preg test is negative, you're not pg (at least not far enough along for OPK to detect)
Once you've ovulated, LH and estrogen levels decline (there is a good graphic here)
Menstrual Cycle: Biology of the Female Reproductive System: Merck Manual Home Edition