Pelvic pain

Okay, so I had my daughter a year and 2 days ago. Normal vaginal delivery, no complications. I’ve been having a pretty regular period the last few months. Unprotected sex with my boyfriend for over a month, no birth control. The past 3 or 4 days, I’ve had a full ache in my lower left pelvic side. Each day it’s gradually gotten worse. Its also progressed to a full ache in my lower back at the same time. Today, work was miserable, and since I’ve been home it’s been worse. It comes and goes just like contractions. When the pain first started, it seemed to ease up when I sat or lied down. Now, even after sitting in a hot epsom salt bath, it keeps coming sharper and sharper. My roommate is convinced it’s an ovarian cyst, which I’ve never had before, and won’t give me a ride to the hospital or doctor, as “they won’t do anything for a cyst.” I’d at least like to know what it is to be safe, but am currently unable to do so. I’m sure it’s pointless asking the internet, but have you all ever experienced something similar? What did it turn out to be?