If you have a 28-30 day cycle, and it began on the 3rd...ovulation probably happened on or around the 15-20th. You are nearing the end of your cycle, so by that method of figuring, you are probably safe. But.....you do know it's okay to say no to sex. If you are that scared of pregnancy, saying no to sex might be a good option.
You can take the morning after pill within 72 hours of birth control failure, which can help to prevent pregnancy. The sooner you take it, the better, and you still have a small amount of time left to do so. Otherwise, you'll just have to wait and see what happens. You can take a home pregnancy test 2 weeks after having sex and get an accurate result. Hope it all goes well.
Also, my period symptoms stopped and I haven't felt any cramping today.