Opk question!!

So this is my first month tracking my ovulation with these. I've been getting lines that's lighter than the control line but getting darker each time. My last one I took wasn't super dark so I just put in in my drawer with the others with the cycle day written on it. Later on I went to the bathroom and looked at them all (I have no idea why, guessing just hopeful to happen soon) and I looked at the last one I took and it was dark as the control line!