Persistent low grade fever

Hello im a 23m 5'7 188lbs I am on Adderall and a non smoker.

Ive been having this issue for quite some time for about a few years now and honestly im getting pretty sick of it. Pretty often during the day or night I get a low grade fever between 99° and 101° it can last for a few hours then goes away. Ive brought it up to my doctor but he kinda dismissed it saying that anything below 100.4 isn't a fever but im really tried of feeling cold and gross when it hits.

Is there any other reason that could be causing it?