19 years old & Im scared of a breast lump?

Okay, Im 19 years old and about 3 weeks ago a noticed a lump in my left breast near my armpit, it was hurting b/c I was about to start my period and my boobs normaly hurt around that time, iv posted this question then but that was before my period now my period has come and gone and the pain is gone but the lump is still there it moves around and i dont really notice it and it doesnt bother me, but it does get a little sore. I have done some rearch and i have no change in my breast, my nipple is not inverted, theres no rash or change in skin color my breast looks normal. cancer does not run in my family at all, but my mom did tell me she has cyst in her breast, could this be a cyst? or developing breast tissue? should i be worried? Im kinda freaking out and id like some advice if this has ever happen to you or your a nurse/doctor please give me advice! idk if this has anything to do with it but im a virgin and i have not been to a gynecologist yet, but I do want to set up a time to go. please help or give me advice if you can, thank you!