masturbation question

when i rub myself and cum, it aches and burns deep in mu vagina for a little then goes away. It was spur of the moment masturbation. does anyone else have this? what is this? i dont have any STDS

is it normal?

it is caused by blood flow in that area. when you are aroused it causes the area to be engorged with blood but after climax the blood takes awhile to circulate back into other parts of the body for some persons so thats why you are having a burning feeling.