pillow4: think read somewhere tt the OPK may remain dark for coupla days, maybe ya've caught the LH rising on 6th itself then on 7th itself, caught the LH surge going down (but still strong enough to be detected on the strips), so maybe O or gg to O soon ler..
Coz am also perplexed over the weird 2 days positive tt I got, then searched abit online.. If got energy, no harm BD, coz tis like every mth (if cycle's regular), only got those few chances to BD, then just work during those days (alternate days or so), then can take the rest of the month off... heh heh..
If lucky enough to strike, the OPK may remain positive etc, but it is not too encouraged to use OPK as HPT to test for pregnancy.. Best's still to use HPT to test for pregnancy..
http://www.ovulation-calculator.com/node/1432
The chemical make-up of LH (LH is the hormone that triggers the release of the egg and is very high prior to ovulation and causes a positive result on an OPK), is one thread short of being hCG (HCG is produced by the placenta during prenancy and it is what HPT's look for). That is why you will not get a + hpt if you are having your LH surge, but you will get a + OPK if you are pregnant, that one thread that is in the hCG, but missing from the LH is what makes the hpt work.
http://www.soulcysters.net/showthread.php/50604-OPK-s-used-as-HPT-s-%28all-questions-answered%29
BD maybe abit tiring but the wait/ anticipation's kinda stressful but yet hopeful too.. heh heh..