The Period That Wouldn't End

Y'all my period has been going on for ten days now and has been a lot darker than normal. You know like that brownish dried blood look? For ALL ten days. I'm on ortho tri cyclen and I called my OBGYN this morning because I know that a million and one things could cause this and I was starting to get scared. I just went and gave blood for a pregnancy test my boyfriend has only been with one other girl and it was her first time too so STD really shouldn't be a thing. Him and I use protection (condom without condom we pull out) and I'm pretty good about my pill but sometimes I do miss and have to double up the next day (which is what my doctor says to do) but I've been under a lot of stress lately. I'm just scared cause those are some pretty big words as possibilities. Has anyone had this happen to them? Any advice or prayers would be appreciated. Sorry for the long post.