I feel like I'm crazy but...

Is toothpaste/brushing your teeth a normal thing to have an adverse reaction to? Im about 5 weeks and yesterday and today I gagged horribly while brushing my teeth. I felt nauseous from it at least for a few minutes and definitely thought I was going to throw up. I left a message at the dentist office for suggestions, but I'm wondering if anyone else has experienced or even heard of such a thing and has any advice.