I'm scared

So this is my first job and I've had it for about 2 months. I strained my shoulder really bad yesterday and I'm going to the doctors today to look at it because I can barely move it. My mom thinks im being melodramatic and it's just regular aches and pains but it's more intense than that. I had to call into work and I told them everything (we do it through text at my work) and my mom said they were gonna fire me now. Would they fire me over something like that? I'm scared I don't want to lose my job but I really can't work like this.