My TSH is normal in the blood test 3 month before I found pregnant. At 9week5days, my blood test Free T4:2.42(normal 0.89-1.76), TSH < 0.004 (not detectable), no symptoms. At 13 weeks, Dr. started me on PTU, I took it for a few days (day1 PM only:100mg, day2 AM+PM: 200mg, day3 PM only: 50mg, day4 AM only: 50mg) on day 4 AM, I did another blood test: free T4: 1.53 (normal), total T3:220 (60-181), normal for pregnancy woman, TSH: 0.004 (this time detectable at the minimum).
My question is: did my T4 drop because I am on PTU for just 2.5 days, or it is more likely the 4 weeks time in pregnancy made a difference even I had not taken PTU? Am I still considered "hyper" with just TSH abnormal? Should I stop PTU?