Having sex for the first time can cause light bleeding but if you do think you may be pregnant you should wait until you're supposed to have your period to take a test. As far as the cramping and frequent urination you could have an infection or STD. Urinary tract infections are common in women or it could be your kidneys, but you should see your Doctor to make sure everything is okay, whether you're pregnant or not.
Spotting and cramping is not rare when it is the first time You are having sexual intercourse it happens quite a lot and I highly doubt after only two weeks that You would be experiencing signs of pregnancy.
You should see Your doctor however sexually transmitted diseases as well as infections can cause more frequent urinating.
Better to be safe than sorry, goodluck
The first time you have sex can easily cause spotting and cramping. Frequent urination can be an infection, more intake of liquids than normal or just going more. You don't actually need a reason to feel certain symptoms, and just having them doesn't actually mean pregnancy. Ovulation can also cause a small amount of cramping, as well as spotting as well. So can being on birth control pills. If you want to test, you will need to wait until your next period is due. I honestly doubt very much that you're pregnant, so try not to worry.