Sould I tell my bf about problems with my health?

My bf and I both go to med school, I live in a different country, so I had to go back home for the summer to visit my parents. My bf was both sad that i'm leaving, but happy that he'd get to hang out with his friends. I didn't mind it, obviously. while I'm home I went to the doctor because my breast was hurting. They told me its fibroblastoma that should be surgically removed. I send my bf a text where I briefly explained it all, and asked to call me back . To which he replied that he is with his friends and he can't talk. it has been like 12 hours, he still hasn't call me :( we talk almost every day for about 15-20 min about our day and stuff... it's not like he got tired of me, I think. im upset and kinda scared even though fibroblastoma is not cancer and I will be just fine. maybe his reaction wasn't that bad? should I even tell mt bf about any health related issues im having? What if I scare him away... or something