WELCOME, Gurpreet!

The HLA B27 testing is flawed, producing many false-negatives. Your symptoms are very common in AS; women present differently than men and usually have more upper body activity early.

I had terrible costochondritis lasting many years and the only thing that eliminated it was the NSD: "The IBS Low-Starch Diet," by Carol Sinclair. Also, please check out the NSD and Diet Forum here.

HEALTH,
John