Well me and my boyfriend had unprotected sex and the next day after I felt cramping then 3 days after I started bleeding it stop after I wipped but I still feel the cramping and my back also hurts What could this mean?

Is it anywhere near your expected period? It could be pms. If not, then you'll need to take a test, although most tests you have to wait until around the time you expect your period anyway for them to be accurate.

Its not because I had my period on the 14th of February

Only thin you can do now is wait and see.

Are you trying to get pregnant? If not, use protection. And if you're not pregnant, consider talking to your doctor about all of your birth control options.

If you are trying, best of luck.