I have a boil like lump on leg small but hurts alot what is it do u think it's contagious are boils contagious before the pus comes out I'm scared?

Keep area clean. The boil on the leg should be kep clean and washed daily. The are is not contagious if it is covered and washed appropriately. If the area grows increases in redness and pus continues to drain would recommend visiting an urgent care for possible drainage and antibiotic treatment.
Boil. It may be a skin infection but it is unlikely to spread. I would wash with an antiseptic soap and warm water.You can also apply an antibiotic cream but stop worrying.