Peeing out blood?

So 2 months ago my friend had unprotected sex and hadn’t gotten her period since then. Then around 5 days ago she went on a juice diet then suddenly yesterday we were out for dinner and she was in quite all of pain then when she went to the bath room she was peeing out blood so she put a pad on bu no blood was on the pad yet when she peed again blood still came out but she said she’s almost sure it isn’t her period as there didn’t look like much pee she could only see blood.

Do any of you have any ideas what this could mean?