Missed a first week's pill - ortho tri cyclen lo. Nervous & stressed!

Yesterday I looked at my pill container and noticed my days were off. I had somehow missed a pill in the past couple of days. I take a few other pills along with it so I don't know how I missed it! I'm scared because I have no idea which day I forgot to take it. It was a white pill in ortho tri cyclen lo. I'm very strict on when I take my pills because I know you should take them at the same time every day. I took two of the white pills last night. I'm scared I didn't "catch" it on time and it's too late.

I start my new pill packs on Wednesdays, (somehow easier for me to remember than Sunday), so I started my period on the 16th, it ended on the 21st/22nd. I have since then had unprotected sex a couple of times (24th & 25th). I'm stressing out that everything has just fallen into the right days and I'll end up pregnant. I believe I'm past the 72 hour mark for the Plan B. What should I do? Any advice from anyone would be great.