Sick every month with little to no fever?

I am a 28 year old female, 4’10 138lbs. I take levothyroxine and a birth control pill. I also take Azelastine and Nasonex for allergies.

So I’ve been a teacher and worked in schools for about 7 years. I’ve gotten sick countless times because of this. However, more recently I‘ve been getting pretty sick but not like I normally do. My whole life, when I’d get sick it was always In my sinuses with a fever over 100F as well as body aches like a normal cold/infection but recently I’ve been having only body aches and fatigue without sinus symptoms and with little to no fever. My fiance has not caught any of these colds from me when I‘ve had them.

Almost every month since November I’ve gotten this weird sickness where I don’t really run a full blown fever but I get some fever symptoms. I usually run a temp around 98.8-99.8. F This most recent time I haven’t gone over 99.1 F. Each time I’ve gotten sick recently I get really bad body aches, and fatigue. My nose doesn’t run, but I do get slightly more phlegm than normal in my throat.( I’m taking two allergy nose sprays to help with daily congestion I already deal with in my throat.) Ibuprofen and Tylenol help with symptoms a bit. The symptoms seem to last anywhere from 2-5 days each time.

My mom mentioned this to my primary care last month (we share one) and she wondered if I could be developing chronic fatigue (my mom has this). I already have Hashimoto’s but it’s pretty well under control and my levels were great in December when I went to the doctor. I’ve dealt with constant fatigue for years and becoming a teacher has really affected this also.

I’m just wondering is it more likely that I just keep getting a cold every month and I just happen to be getting different symptoms than I‘m used to? Or could these be chronic fatigue flare ups? Or could this be something else?