I've also been having the same urges, actually. And the only thread keeping me from stopping myself is inconvenience. SH is something that feels relieving to me, it's an outlet, and a way to reaffirm the comforts of my pain. A way to punish myself for my failures and remind myself of every reason I am here.
SH is very addictive, but very inconvenient at the same time. Trying to shower with fresh cuts is... fucking ouch. I also don't really have a good way to hide the cuts if it were to be on my arms, and the chafing on my thighs with cuts is irritating as all hell.
You're probably having these urges as a coping mechanism, a distant impulse and just a way to relieve internal pain all together. I absolutely don't recommend you start at all, because it becomes such a habit when you really get into it. Please take care of yourself, and look into aftercare if you do end up giving into those urges.
<3