So ive never self harmed befofe but my pms makes me really depressed sometimes and earlier when i was out i got this idea that when i got home i wanted to take my pocket knife i had and just see how far i could go, i want to see if i could break skin. My day went on and I experienced mood swings so my day ended pretty good but i still kept thinking about cutting even tho i didnt feel so bad anymore. Basically i did it anyway, i didnt break skin or even really hurt myself that bad, but several hours later i noticed marks on my arm. I dont want anyone to worry so how long do u think the marks will be there? I didnt break skin, i didnt bleed so im confused on why there are any marks at all?