I had unprotecteded sex 3 months ago i've been getting my period every month since but this month it's coming 2 weeks early. should i be worried?

Probably not: Sperms may be masters of deceptions, but dont have that long staying power! If that encounter was to reult in something, you would've known earlier. In any case, a simple urine pregnancy test can rule out any concern. For the future, try not to have sex without protection, both against pregnancy and STD.. Feel good!

No: You are not pregnant from the previous encounter however you should be worried that you allow unprotected sex and may consider seeing a health care provider to check for sexually transmitted disease.