GBS possiblity?

Currently I'm experiencimg GBS symptoms. Had abad tummy last Sunday and after 2 days had some numbness in leg..now it's progressed to both leg, knee area।।hand pain ,hip pain The thing is I earlier had joint pain so not sure whether this is that or GBS I stay in kharadi area. I had on last Sunday but if nausea n bad tummy ..it settled . Can blood test detect GBS.