ALS is a strange beast. Some of us started out with atypical symptoms and others, more commonly, developed foot drop or slurring their words.
I will say that other "issues" come along with ALS and you can have things going on that are unrelated to the disease but makes life a whole lot harder.
I was diagnosed with Meniere's disease years ago. I had all the symptoms except hearing loss. I went to specialists in Florida and they all kept telling me the same thing. Eventually, I went to University of Pittsburgh Balance Center where a world-famous "dizziness" specialist ran me through two full days of testing. The results came out cervicogenic vertigo, migraine associated vertigo, and a dislocated TMJ. Both vestibular nerves were compromised. I still have all the symptoms but there is really no cure so I medically manage most of it. I've also had bladder issues and an anal fissure secondary to constipation.
I'll tell you my story because I'm classified as slow progression, too. In 2012 I sprained my left ankle just standing up. Now prior to that I was a runner, played golf, soccer, basketball, scuba, and biked. I was a gym rat, extremely muscular and at 5'6" I never weighed over 110 pounds. I had to eat lots of calories just to maintain weight because my metabolism was fast. So my ankle healed and I was back running, not as far and not as fast. In 2013 I fell running and didn't break my fall. Suffered a traumatic brain injury and had to do a lot of cognitive rehab because I lost 60 IQ points. During the rehab, the did extensive testing and found that my left hand had moderate to severe motor skill reduction. I played piano so I already knew this but didn't put it together with the fall. I also started to have trouble getting change out of my wallet and I dropped things more. In 2014 I developed cramps and twitches in my left leg and foot. By then my local neuro decided to give me a thorough physical exam, lots of blood work, and do an EMG. After everything came back he referred me to Mayo. I waited about 6 months, then made an appointment. Mayo did a clinical exam and I was still very strong but I knew I was nowhere as strong as before nor did my body look like it did before. When they did the EMG they changed their tune and said possible ALS. I already had brisk reflexes and some other signs like atrophy in my left arm, hand and shoulder but this going back and forth finally led to a diagnosis in 2015. I got a second at Johns Hopkins. Still not believing it I went to two more ALS specialists.
Just thought hearing another story might help.
That said, I would definitely get to a specialist for a new EMG, second opinion. Two other tests that, I believe are necessary, are a comprehensive pulmonary function study (including breathing muscle strength) and probably a swallow test.
Meanwhile, don't fall. I did and it really hurt my ability to take long walks. At the time of my fall (2016) I was still walking one or two miles a day. after the fall ( I twisted my GOOD ankle carrying four bags of groceries and didn't see the curb) I had to hop around on my bad leg and my back suffered. It took a good six months until I could walk 1/2 mile again. Now I can walk about 1/4 mile on a good day. I think the fall in 2016 made me progress faster.