Back pain and spotting roughly a week after period has ended and I'm worried

I've been having a dull ache in my lower back and slightly in my pelvic area for a little over a week now and the first time I noticed it was shortly after my period ended. It started in my pelvic area on the right side and was a VERY dull pain that I only noticed when focusing on it or moving a certain way and as far as I know I wasn't having any other symptoms. Now it's mainly in my back, my pelvis only hurts (sometimes) if I sort of suck in my stomach or twist the wrong way. The pain in my back is usually very mild, sort of like a burning sensation , and it'll only flare up once in a while and then almost disappear before the process repeats. I've felt around my abdomen and I don't feel any lumps, although it is sort of tender but this goes away the more I mess with it. 
Now, over a week has passed since my period ended and I've started spotting. Its not heavy, and it started out brown, went to pink, and now it's back to brown. It's been going on for about 3 days now and is usually only once a day which is strange. Other than this I feel fine and haven't noticed anything else unusual (besides being slightly gassy but that could be from anxiety or a number of other things) but I'm still worried sick, I can't go to the doctor because I don't have health insurance and it costs an arm and a leg just to get seen. If it continues I'll go and get blood work done but until then posting here is the least I can do. I am NOT asking for a diagnosis, I just want to see if anyone has experienced this before and if so, any advice or opinions are very appreciated. I have horrible health anxiety so I've convinced myself I have some sort of cancer and I'm freaking the hell out even though I know that's unlikely at my age (18).
Also it's probably worth mentioning that I'm not sexually active nor have I ever been, I'm not on birth control and I've never experienced anything like this before. I've had spotting but it was only once by itself a long time ago. All of my periods seem normal to me and haven't been super painful either. I don't know if the back pain is related to the spotting or not but I don't think there's any way that can be purely a coincidence. If anyone has an idea of what this could be or has had something similar, please let me know. <3
📷ReplyForward