catheter

I'm 10 weeks pregnant . Today I went into the doctors to get an ultrasound. They stuck a catheter in me. It was very uncomfortable. They said everything was okay. I went home, took a nap. Woke up and went to the bathroom. As I wiped I noticed light pink blood. Now which only happens when I go pee. Has anyone else had any bleeding after a catheter? And if so how long does it last? This is my first pregnancy so I'm very worried.