Losing some hair in the shower is perfectly normal and nothing to worry about.
Even if you find some clumps of hair in the shower when washing your hair that's still very normal as we lose around 100 to 150 strands of hair when washing our hair.
We also sometimes lose hair when brushing our hair or combing our hair which is also normal as it's just shedding the older strands of hair to make way for the new strands of hair that are ready to push through our heads.