Question that's bugging me

We have been TTC since September (August I had my mirena removed) I have been taking my prenatals Every work day m-f. Sat and Sunday's I usually forgot them since I would leave them at my desk at work. Dec 25- Jan 4 I did not take any prenatals I went on vacation for forgot them.
I didn't think December would have been our rainbow month since we were only "active" 1 time during my fertile window (due to his work schedule) however out of the blue I took a test and we are having a baby!! I started up my prenatals again but I'm so angry for missing those 12 days