I bought a set of ovulation tests about a week ago. This week should be my week but when I tested I just became more confused. It says that the 2nd line has to be a dark or darker than the first but I haven't seen it. I saw one day it gets its darkest out of all the tests but that was it, then it just got lighter. Is there a time of day I should be taking these? Does it truly get a dark or darker?