Should I go to the doctor? Help please

Hey guys, so my last af was 9/30 so I missed my October period and I’ve just had this weird feeling that I am pregnant but all the hpts are negative so I gave up and just a couple days ago I started getting really bad back and pelvic pains on and off. At first I started bleeding like a clotty black looking substance (lightly) and now it’s just spotty black. Anyone know what I should do or had any experience with this? I’m kind of concerned. I’ve been out of work due to the pain.