Could any Doctors or Nurses out there answer this? I'm scared, could I be having early symptoms of ALS?

I'm an 18 year old male & I've always been in great health. I just had a doctors appointment not too long ago & my doctor has never been more impressed with my physical checkup. Yet I still worry about my health... The most recent thing I've noticed is my pinky finger on my right hand. I'm a righty so when I hold my phone, I usually hold it in my right hand to text, and balance the base of the phone on my pinky finger. When I do this, my whole pinky shakes & therefore causes my phone to wobble. Also, I just bought my first laptop this past weekend, and every time I use the track pad to scroll down a page with my index & middle finger (still right hand) when I'm finished, my pinky feels numb/sore. I get the occasional muscle twitches throughout my body, but then again a lot of people do. My family has no past of Parkinson's or ALS to my knowledge, but I'm so concerned. Is it also common for your hand/fingers to somewhat shake when you hold it out in front of you? This really has me scared, I keep thinking I have a very serious illness such as ALS or something else. Thanks in advance for your input.