Hi I'm 18 years old (female) just about three days or so I've noticed a lump forming from my lower butt cheek to my anus and vagina its very painful to sit or get comfy laying on my back at night it hurts with and with out me touching it and while I use the bathroom it sends shocks and pain to the point that I can't sit and pee when I try to take a poop it hurts even worse I've tried warm compresses and tried to take a picture of it to see what the matter was but I can't seem to find anything. I am sexually active and a slight chance of pregnacy but I'm not sure. Also I wouldn't know how to tell. I'm trying to figure out what to do or what it is because its very concerning to me and uncomfortable.

If anyone knows what this is please tell me and what should be my next step

Thank you