Today I used my first ovulation test just trying to watch my cycle a little more closely. I assume I will ovulate this coming Wednesday as the first day of last AF was 18th May, and normally I am bang on 28days. So today i tested and a faint second line came up. The packet says this means you will ovulate in the next 24-36hrs. So if I test again tomorrow and the next day will the lines get darker as it gets closer to O and on O day??
Or do I just assume it will be the next few days considering the second line??

Thanks in Advance!