I have starting stuttering all the sudden and no logical explanation why

I have starting stuttering all the sudden and no logical explanation why I have always had a speech impediment. I can't pronounce words for shit and I jumble my letters. I have never had trouble with stuttering though and over the last 3 weeks I have started stuttering quite often. I don't take any prescription drugs and I don't have any childhood trauma. Can this just happen all the sudden with no explanation? I'm going to look into going to my doctor, but I was just wondering on personal experiences and advice. Thank you!