opk help?!

I'm so confused. we've been trying to conceive for about 5 months now & the only main focus i've had for tracking is OPKs. but now i'm not so sure about how reliable they are?! unless someone can explain. i use the clear blue advanced ovulation sticks. well yesterday i was low, i take one today & im peak? what happened to the high days in between? why is this so confusing! help!