I dont now what to tell u but on sunday I had sex to with this guy and he accidently cummed in me and I dont know if im pregnant or not

I would highly doubt that you would be pregnant.
Ovulation had already occured.

Pregnancy is possible even when you're on your period (especially so for those with irregular periods). Ovulation time, though generalized, isn't the same for every woman! Pre-cum does still contain some sperm too. However, I doubt you're pregnant (if you still believe you may be, take a home pregnancy test or see your doctor for a blood test); I can only say I hope in the future you'll use protection and if you're engaging in 'risky behavior', please talk to your doctor about at least some form of birth control. Good luck.

Ovulation occured already. If your period came the day after then your unpretected sex is not going to get you preggo.... Please use a form of birth control especially if you are not ready to be a mom.