Marathon training plan mixup

Hi! I have a slightly embarrassing question… I have been following this training plan for the Philly marathon (my first marathon) but I realized I’m one week off so I’ll finish the plan a week before the marathon. 🤦‍♀️ I started at week 8 (I’ve been running 10-13 miles every weekend this summer) and I am currently at week 13 so I’m planning to run 18 miles this Saturday. Does anyone have advice for how I should adjust the plan and add another week of training in?

P.S since I have you here. My goal is to run sub 4. I run most of my long runs at around 9min/mile and can chat and my heart rate never gets above zone 3 (according to my Garmin). My weekday longer runs are around 8:30-8:40. All of the advice I’m seeing is to slow down but I just get so excited at run club on Saturday’s that I end up running faster than I mean to but I feel good! Is this okay?