As earthmama said, this could be something simple that can easily become something much much more complicated. And as others have said, any number of things can cause blood to appear in the urine.

Its the weekend right now, so chances are you won't be able to see a doctor right away; however, you should see one first thing on Monday and sooner (as in ER) if you have any of the following symptoms: fever (greater than 100.0), flank pain (mid back towards the lower ribs), vomiting, or worsening of current symptoms (eg. darkening of urine, increased urinary frequency, increased pain on urination, chills etc.). The procedure to determine whether or not you have a UTI is very simple (as said before, you pee in a cup and they can tell you within a few minutes if you have an infection). Chances are they might put you on antibiotics any ways simply because of your symptoms.

If this becomes a recurrent problem, you may want to look into finding a good urologist to see.

As a health worker and some one who personally has struggled with urinary issues before, I urge you to seek medical help for this as soon as possible. I know doctors can be scary, but maybe you can take a friend with you who can help advocate for you. Come up with some questions before you go so you know what to ask when you get there. You can even list symptoms if you have a tendency of forgetting when you get to the doctor.

Most health care people are genuinely there to help. Please remember this. I know that some doctors (and nurses) aren't the best at there job, but that is the same as any other profession. You have good and bad ones. Don't let that stand in the way of your health (and then when you get well, try finding a primary health care provider whom you trust and feel has genuine concern for you/listens to your concerns). Good luck!