I've been TTC #1 after we lost our first angle at 5 weeks in october. I just started using opk test strips this cycle but I can't tell if they are working. I keep getting a line its just never quite as dark as the control line. The darkest one yet was this morning (CD20)I have a normal 28-30 day cycle and 3-5 day period. Did I miss it? might I already be pregnant? please help!!!