I have went from 25 to 50mcg of levothyroxine and i still don't feel any difference. this is my 4th week on 50mcg. can i request another blood test?

Yes: It takes 3-4 weeks to reach steady state with regard to thyroid labs. Keep your expectations low. Thyroid changes are subtle.

Yes you can: The "average" hypothyroid 28 yo male will probably need about 125-150 mcg per day. After 4 weeks of 50 mcg, if your TSH is still high, i would advance the dose faster (assuming no heart disease or other confounding factors).