Can someone tell me how soon after conception TSH rises? I have Hashimoto's and have been on 125mcg of Levothyroxin for 2-3 years. My last blood test in May showed TSH 1.something. My bloodwork from last week put me at 6.06! That's a huge change, but, there is a chance that I am pregnant. If I'm pregnant, conception would have occured between 11/15-11/18. Does TSH go up that quickly when I'm just "barely" pregnant?