Could I be pregnant? Has this happened to anyone else?

The past couple of days I have been irritable, my breast feel full and hurt most of the time for the past couple of days, I have been getting light headed and a little bit nausea here and there, my appetite has definitely been bigger, I have had some light cramping but not anything like I usually do because I have PCOS and endometriosis. I had some brown discharge for like maybe 2 days . My period was supposed to come 3 days ago . The biggest thing being my boobs are killing me . But I took HPT and they are negative . Should I go to the doctor and get a blood test in the off chance that something might be up with my urine to where it can’t be detected in my urine ?