Suspected MG, negative tests so far, SFEMG pending

I've been under treatment since a month and a halve

Experienced first symptoms, like fatigue and problems reading things up close after my first covid infection in the beginning of 2022, but attributed all the issues to getting older

In short:
I have had multiple tests which came out negative, I'm on mestinon and am waiting for Single Fiber EMG test

Heat can trigger or worsen my symptoms

Because the tests up until now have come out negative and because when I'm in the hospital I feel well and am not showing the symptoms, I'm afraid the Single Fiber EMG test will also come out negative

It's effecting my daily live and also work, if all the tests are negative I might not know whether my employer will keep on being understanding of my health issues

Long version with background info:
I had extreme double vision after having my second or third covid infection in february

I already experienced double vision occasionally in the last 3-4 years but didn't think much of it because it normally returned to normal

However this time it seemed to come back more frequently and didn't go away in a few hours

I've had the following tests which were Negative

* Bloodtest
* Thymus CT scan
* EMG

My neurologist put me on mestinon when I had an episode and was commited to the ER, this was prior to the EMG test

I did not have breathing issues but was feeling unwell

I normally push through when having issues but this time I felt really off, I called my neurologist and he advised me to check into the ER

That week temperatures were high and my symptoms were really getting worse

Mestinon seemed to help I got a low dosis at first I was given 3x 30mg a day but when the high temperatures continued and I got a list of other symptoms it was increased to 5x a days

I kept a daily report on how I was feeling but because of the list of other symptoms I listed the neurologist told me he's not entirely sure I have MG

He referred me for a Single Fiber EMG test which I'm still waiting on

My frustration is that everytime I go to the hospital for tests I feel reasonably well, they have not seen my droopy eyes or strength loss while I was there

I have told them multiple times that my symptoms can be triggered or worsened by exposure to heat and that my issues can start in the middle or later in the day

My fear is now that when I do get the Single Fiber EMG test it will also come out negative

The past weeks have been tough and I have felt like I was surviving on a daily basis, the higher mestinon dosis has helped but feeling good or bad is still fluctuating throughout the day