Its WAY to early for pregnancy symptons and these are very common side effects for emergency contraceptive.
Your period will likely be slightly irregular for the next 1-3 months and you may experience spotting between periods.
If you don't receive a period next month then take a pregnancy test. Also, you may want to look into using a more reliable form of birth control if you are not comfortable with just using condoms. It will save you A LOT of stress in the long run.