Plan b plus birth control

I take Sprintec (the combo pill) and I have yet to miss a dose, but I did take it late twice this month by accident and also have been on antibiotics for a UTI. I had unprotected sex the week of my period (my placebo week) and went ahead and took a plan b, JUST IN CASE because I didn’t feel informed enough to take the chance. From what I have read, I’m still protected on the placebo week… can I get some better inside to this? 😊 TIA. I feel like with the BC plus the plan b, I should be fine. Just feel like I can’t get the info I need and my OB is closing down. Please be kind. Thanks in advance