Last Week I Started Taking A New Drug Sertraline(zolof) 100

last week I started taking a new drug sertraline(zolof) 100 mg. I misread the doctors directions and started taking two a day when I should have only been taking 1/2 pill a day for 7 days and then one pill from then on. I took 2 a day for 5 days before I realized I was taking too much. I didn't feel any different and didn't appear to have any side affects from it so I never mentioned it to my doctor. Last week I went to my prime care doctor and he said my thyroid gland is swollen. He wanted me to get a some type of scan on my neck. Do you think the swelling could have been caused by a overdose of zolof?