For me when I do them a little higher, right at the level of the belly button, but not too close to the belly button, I have better luck there. I get bruises when I do it as low as you did it. Not sure how old that one is, but take my advice about the heat. Give it at least a day after the bruise appears, but then put heat on it a few times a day for 10-15 mins. You'll be surprised how fast it starts to dissolve. Hang in there, sweetie!
