You alwasy have LH in your system around ovualtion you get a LH surge, If the line is lighter than the test line it means your not ovulating , when you are ovulating you get a very dark line as dark as the test line, to judge whether you are pregnant or not using an OPK is very tricky as you always have the Lutenizing Hormone in your system. But if it is very dark and you know you have ovulated that could be a good indication of conception, bottom line always back it up with a hpt and HCG blood test