Trying to figure out if I’m Celiac

I’ve been having bad symptoms and digestive issues since 2018, and before then I don’t recall ever feeling as sick as I do now whenever I eat, more specifically since last June I’ve just been having a lot of the basic digestive symptoms

Towards the end of last year I brought it up to my PCP (not the first PCP I bring up concerns to) and she said it sounded like IBS but did a blood test to see if I was celiac (which came back negative)

I saw a gastro (an overall short visit) before she declared it IBS and sent me on my way, I’ve been trying different things to help it but I’m still getting sick, I have okay days and then really bad days

My question is, has anyone tested negative on the blood test but then done an endoscopy with a biopsy and tested positive? Should I really just accept it’s IBS or should I pursue the biopsy to confirm? A lot of the symptoms overlap, but worth mentioning I’ve been anemic and borderline anemic since the first time I started having digestive issues in 2018 and I just can’t help but think it’s related (I’ve also been told I have smaller than usual red blood cells, the internet says it’s microcytic anemia)

Any info helps, I’m new to all of this and have been suffering for a while and I’m just trying to get answers because my mental health has taken a hit with all of it, thank you!!