Implantation vs ???

Hey, I've been spotting randomly mid cycle, which hasn't happened in years. I have had unprotected sex, but I'm also worried I may have fibroids or cervical cancer based on other symptoms such as darker urine, massive amounts of pelvic plain and bleeding after sex recently. Has anyone experienced anything like this and have any advice? I'm not sure how to differentiate between an illness/medical concern or pregnancy. Any advice or positive vibes would be appreciated!