You don't need to wait until your period is due to know whether or not you're pregnant, because I can assure you, you aren't. I'm not a doctor and I can't officially "diagnose" you but I can tell you from nearly three decades of life that you absolutely need to have intercourse to get pregnant.
If you have not had sex (intercourse), then you can not get pregnant. You didn't have sex, so you're not pregnant.
That being said, "messing around" unprotected still leaves you vulnerable to sexually transmitted diseases (STDs) and sexually transmitted infections (STIs). So it would be a good idea to check out https://bedsider.org and see what methods of protection are right for you and your partner to protect the both of you from STIs and STDs. Likewise, before and after getting intimate, you and your partner should wash your hands.
If April 18th comes and goes and you still don't have your period, then you can take a home pregnancy test for reassurance. However, you should remember that stress (like stressing out about getting pregnant) can delay your period.