2 days ago i noticed blood on y arm it was a very small scratch/skin peeled. today, i noticed the same place bleed again. should i be worried?

Worth a checkup: It's not much to go on, but this could be how a pre-cancerous skin lesion called an actinic keratosis presents. Small skin cancers such as basal cell carcinomas and squamous cell carcinomas also often present this way. It could be nothing, but i think this is worth getting checked and probably worth a small skin biopsy to be sure that you are a-ok.

Might have reinjured: You might have reinjured without knowing, or rubbing againt clothes or some thing else if it continues to bleed, than see your doctor.