It's hard to say but a blood test will answer that question for you. Some women home pregnancy tests just don't work early on. But also there can be many reasons why your period is late. The main one being stress. If there is anything different or new in your life- school work boyfriend- it can all do it. I wouldn't worry (so not to stress as much) until the blood test is done. No reason for stressing yourself out if there's no reason. Also if you're not wanting to become pregnant start using condoms or sown sort of birth control. If it hasn't already happen you're just creating a higher chance with unprotected sex. Keep us updated and your more than welcome to message me if you want to talk or just vent!