What Causes Urethral Bleeding?

im 27 yr old female. i felt like i was comin on for my time of the month and when i went to the toilet it was bright red blood, but it wasnt comin from my vagina! then 6 days later there was a small bit of blood in my toilet again but just a very small bit. there is no discomfort and this is the only 2 times its happened? could i pregnant?