Possible symptoms

I am currently 13 dpo and so far have only gotten bfn af is due on 9/23 and I’ve had a constant headache as well as lower back pain and my butt hurts like really bad even while just laying down like I’ve fallen on it really hard (which I haven’t ) my boobs are tender off and on and just last night I started having cramping in my pelvic area when I was pregnant with my daughter I had lots of back pain and nausea but I don’t know what to think with these symptoms I’ve been experiencing now what do you guys think I just orders some first response test they’ll be here Sunday