Metallic taste

I had a metallic taste in my mouth after I took plan b. Can't say exactly how long after, about 2 1/2 weeks after while I was spotting. But I most definitely got my period after a few days of spotting, it was heavy "bright red" blood. I'm thinking it was my nerves putting a bad taste in my mouth. But I looked it up and it's a symptom of pregnancy too. I'm positive I'm not pregnant but has this happened to anyone else?