I’m no longer allergic to dogs after 15 years?

I’ve been severely allergic to dogs since I was 5f I’m 19f now from 16-18 I spent everyday at my friends house who had 3 dogs then when I was 18 and a half I wasn’t having a reaction to his dogs anymore. Now I’m 19 and my bf has a dog and I’ve never had a problem I’ve petted her and been in the room with her for a long period of time. I’m not sure if my allergy went away after 15 years I’m not even sure that’s possible. I know it’s not as important as other peoples posts on this subreddit but any answers will be lots of help.