Cooking leg of lamb from iceland that says cook from frozen, how i do i know when its done?

its been in about 2 half hrs and when i checked it blood squirted out. its a 2 kilo leg, looks done but im concerned about the blood, should i have no blood, it was from frozen not de frosted cos it said u dont need to thaw it from iceland. shall i leave it in till no blood or untill its a nice colour.i never cooked a lanb before and dont want to poison everyone