Strange mark on breast?

I’m not really sure if this comes under this topic, but I’m worried. Around a month ago I noticed this mark on the side of my breast and I’m unsure of what it is. It doesn’t itch or hurt and I don’t think it’s grown, but it’s stayed this week for the last month or so and I’m getting worried. It’s kinda’ showing between my breasts too, above my cleavage. Does anybody have any ideas? I’m 19 years old, but I keep seeing things like inflammatory breast cancer and it’s just scary.