Well, did you feel dizzy or anything like that? If it's not a really large amount, blood regenerates itself pretty quickly. I don't think it should be a problem, but I don't know how big of a cut this was either.
If it's stopped bleeding and you feel completely fine, I'd say it should be fine to roll. I don't think blood loss will effect a roll at all honestly, I'm pretty sure you'll still roll even if your dying from blood loss, it's more of a matter of how safe it is to roll. If you haven't lost enough blood to make you feel really dizzy or anything (and remember, people donate a pint of blood at a time and are fine) there shouldn't be a problem. I've rolled the same day as donating blood, and was a-ok, and I doubt you lost more than a pint.