What Causes Pus Filled Lump On The Leg Along With Severe Pain?

I felt a sharp pain on my leg,last night when taking off tights for a shower,o I did shave but have not ever gotten ingrown hair,but it burns and stings and kinda throbs, it got a pus whitehead so I poked it with a needled twice first time some came out but the pain spread around and skin feels sore did it again it really hurts not sure if series or not,