Docta. I am also a cancer survivor about the same age as you. I have been twitching for five and a half years, I've had the lump in my throat, I've had plenty of health anxiety, and I get terrible muscle fatigue. I do not have ALS.
Listen, both of our bodies went through some s**t. Chemo is nasty stuff, and I'm not sure if you had any radiation, but that stuff is nasty too. The good news is we both survived and are here to talk about it, but it's pretty much inevitable that our bodies are going to be affected in weird ways.
It's hard to accept the unknown, but it's better than the alternative. Your doctor said no ALS. Listen to him and live your life. You didn't fight to survive just to be weighed down by irrational fears of ALS. ALS is rare, ALS at age 29 is really, really rare and ALS presenting with twitching is really, really, really rare. The chances that you have a rare disease at a rare age with rare presentation...is really friggin rare. The chances that your nerves and your neuromuscular system are exhibiting some bizarre long term side effects from the chemotherapy? Far more likely.
Keep in touch with your doctors, and definitely follow up with them. The fact that you have some abnormal things on your EMG means that something is going on, but don't assume that something
is ALS. Like you and the report said; you don't meet the criteria.
Best of luck man.