Implantation Bleeding?

Is this implantation bleeding? Not mine. My little cousin thinks she may be pregnant, her last period was 9/30/2021 and before that last she’d been on birth control for 8 years. She had frequent urination, nauseous, sleepy, emotional, tender breast, and had a possible faint positive the other day, (tonight she tested and it was negative or a dud) but for the past 2 days she thinks she has implantation bleeding. Opinions on what could be going on? Is she pregnant? Miscarrying?