Hmmm that is strange they would give a certain amount of days for a relapse to become "full blown". They should know more than anyone that everyone's MS and relapses are different.
With that said, some of my relapses have taken a couple of days...but some have taken longer.
For instance, 3 years ago when I went blind in my right eye, it took about 2-3 days. I woke up one morning and my vision was "off". At the time I had been misdiagnosed with a Pseudo Tumor, so I was being treated with water pills instead of immediately being put on steroids. On day 3, I woke up and my vision was 100% gone. (luckily it came back).
Let's fast forward to only a few months ago. One morning I woke up, and I took a belly flop onto the floor. I hurt my chest really really bad. I noticed immediately that I was starting to get some tingling and numbness, but it was manageable. I could still function and I could still walk, bathe myself, move my fingers, etc.
However, I noticed with each day that passed, it started to get just a little bit worse. I kinda ignored it b/c I thought it was just the residual symptoms of a previous relapse coming back. Then I fell again a few weeks later. When I fell again, it only took maybe a day or 2 and then I couldn't walk at all, my husband had to bathe me, I couldn't move my fingers...I pretty much couldn't do anything.
What I think happened is that I was going into a relapse from falling the first time, but for some reason it was just taking its time.
I could go on and on, but I won't bore you with my relapses. I just think they are wrong for what they are saying. They aren't in your body and they don't know. I don't think doctors and scientists know as much as they think they do. The only person that knows the most about your MS is you.
Good luck with everything!