Talk to Gynecologist on Abnormal Period

I’ve had irregular periods since around age 15. I’m now 20. Birth control helped a little (I have low estradiol) but I stopped taking it in 2022. Since then, my cycles have been irregular, lasting 7-14 days, with breaks of 4-7 weeks. I’m worried I could be pregnant from an encounter 4.5 months ago where pre-ejaculate might've touched my vagina. I’ve had a few periods since then, but I know some women still bleed during pregnancy (e.g., Serena Williams). Recently, I had a 3-week period, which ended but came back a week later. I've also had brown discharge for almost a month, which seems odd since brown discharge usually starts or ends a period. I’m stressed due to personal issues, which I think could be affecting my hormones, but I’m still scared this could be pregnancy-related. I’ve had digestive issues and vomited a bit while brushing recently. I read about ectopic pregnancies, and my symptoms seem to match. I’m afraid to see a doctor because I’d need to go with my mother, and any hin