I'm Taking Right Now Levothyroxine 0.88 And My Question Is

I'm taking right now levothyroxine 0.88 and my question is what would be the effect to me because I just found out my TSH is high and and the doctor give me a prescription for hypothyroidism I need to take this for 2 months and then they and they scheduled me for ultrasound then I am still having my exercise and food diet but still I'm gaining weight