Quick Hamstring Strain Problem

Hi all,

My doctor said I suffered a grade 1 hamstring pull when I was playing baseball. I didn't notice it during the game and played on and only after hours later did I feel a nagging pain. Because of my stupidity, I thought it was soreness just due to muscle fatigue and didn't ice it.

It's been two weeks from then and I can walk without pain, but it's uncomfortable going up stairs, standing and bending my knee back, and the worse pain is during crotching. I haven't really done any exercising after the injury besides walking 10 minutes a day to work.

My question is, should I begin stretching or should I let it rest more? Also, when should I begin to do strengthening exercises as well? Is ice also still effective at this point?

Thanks