This may not apply to you at all but I was in my 3rd week of Methotrexate and I developed a low grade fever, shivers and sweats. I was busy at work so while I did see my Dr., I had more important things to do.
After about a week I developed severe cramping. My family Dr thought I was having a bad reaction to the Methotrexate and kept me in the local small town hospital on a regular diet, taking Tylonol Codenes every two hours for the pain. After three days he sent me 350 miles by car to Omaha where my Reumy was just coming off vacation.
I made it 300 miles and became violently ill and finished the trip by ambulance. After several hours in the hospital, I went into shock and my wife got a surgeon to look at me. I had ruptured my colon. They did emergency surgery to clean up the Gangreine and Peritonitis and took out an 8" section of gut. I had an out of body experience and watched the surgery from above. After two weeks in the ICU and another 4 weeks in the hospital, I went home.
If that were to happen again, I would beg for Cipro or Flagyl from the getgo and would have been well in the first week. The Methotrexate and Prednisone had masked the real problem.
Don't make the same mistake I did.
OH wow I hope you find out what is wrong and that everything is ok!!!
I haven't had issues like that yet on the Methotrexate. (knock on wood) I just get really tired and usually don't feel well the next day after injections. The side effects though are getting much better for me.