Is It Possible That Sex Could Have Resulted In A Vaginal Cut?

I had sex with my boyfriend two days ago, while having sex i started to bleed and it was slight spotting looking blood after sex but it didn't look like period blood but the sorta blood when you cut yourself and it smelt of metal. plus my period finished 4 days ago i'm really worried i have something wrong going on down there. i always use protection and the condom has never broken. i am 15 and female.